Work Text:
“Hey, guys,” Ashido said one afternoon. “Did you hear that an upperclassman came to class to look for Midoriya?”
Katsuki paused his writing, but after a second, his pen continued to scribble out the last part of the math equation he was working on.
“Oh? For what?” Kirishima asked.
“Dunno.” Ashido shrugged, pouting. “She was super pretty, though! Kept asking me and Uraraka when he was gonna be back. And, and, get this.” She leaned, grinning. “She was blushing sooooo hard the entire time.”
“Whoa, no way!” Kaminari gasped. “A crush? A secret admirer? Was she there to confess?”
“That’s what we’re thinking!” Ashido said, bouncing on her seat, but her movements disrupted the table they were sharing, and it made Katsuki’s pen skid across his page.
“Goddammit, Ashido!” Katsuki barked loudly, making his pack mates jump. Ashido, who was an Omega, should’ve had the instinct to cower and shrink away from him, but she was tough and used to his outbursts, so she merely scrunched up her nose and sat up straight.
“Geez, sorry, Bakugou,” Ashido murmured, frowning. “Was just trying to keep some of us entertained.”
“I ain’t a gossip whore like you. That shit’s pointless.” Katsuki stabbed his notebook with his pen, nearly ripping the page from the suddenly violent way he was writing. “Getting all worked up over some stupid girl looking for a stupid nerd like Deku. You must be hungry for drama to make such a big deal over that. If you want some entertainment, get Kirishima to fight a dog outside and see what fucking happens.” When he finished talking, he found himself breathing heavily and shaking, shaking so bad that his penmanship was becoming less and less decipherable. He tossed his pen angrily to the dip between the pages of his book, and looked up.
His pack members were staring at him.
“What?” He barked, skin prickling.
“Uhh,” Kirishima was the first to break the tense silence. “You… okay, bro?”
Kaminari sniffed the air. “You’re not going into rut, are you?”
“Don’t be a creep,” Katsuki hissed, ignoring the first question. “I’m just sick and tired of you dumbasses distracting me from work. If you wanna giggle and fool around like idiots, go do it somewhere else.”
“He’s definitely having his cyce soon,” Ashido quipped. “That, or he’s having a real bad day. What’s up? I don’t remember you losing to anyone in training today.”
“That’s because I didn’t.”
“So?”
“You’re fuckin’ annoying the shit outta me.”
“Breaking news.”
“If you know what’s good for you, you’ll drop this.”
“Drop what? Why are you so agitated? It’s just stupid gossip, isn’t it? Why are you being such an ass, huh, Bakugou?”
“ Okay ,” Kirishima cut in, smiling tightly. “Why don’t we take a break?”
“Great.” Katsuki promptly shut his books and gathered them all in his arms. He got up and left Kirishima’s room, and when he slammed the door shut behind him, he could hear Ashido yelling what the hell was that.
What the hell was that indeed.
Katsuki growled as he went down the hallway, his Alpha pacing and barking in the confines of his body, got to his dorm, and passed it in favor of the stairs.
Once on the second floor, he flung Deku’s door open.
Deku, who was relaxing on his bed reading a comic book, jumped and sat up. "K-Kacchan!?" He exclaimed at the same time Katsuki slammed the door shut behind him, locking it for good measure. "W-What are you— What the hell , Kacchan, why do you smell like that, what's—"
Katsuki dropped his stuff, grabbed the front of his shirt, and pulled him into a harsh kiss.
Deku winced, probably from the way their teeth were clicking uncomfortably, but Katsuki paid him no mind. With his free hand, he tossed the nerd’s comic book to the floor, and slowly eased himself on the bed. Deku whined again, but he was starting to kiss him back. Katsuki’s Alpha preened.
When they parted, they were breathing heavily; Katsuki’s eyes were nearly black, and Deku’s face was flushed pink. “What the hell?” Deku was the first to speak, though his voice was small and husky.
Instead of answering, Katsuki took a big whiff of his room, his hair, and then his neck. Deku made a noise of protest, but Katsuki ignored him, concentrating. He smelled petrichor, pine, annoyance, confusion, and leftover sweat from their training, but he didn’t smell anything — anyone — else. Katsuki hummed, satisfied, then backed off and sat down heavily on the other end of the bed.
A beat of silence. “I’m not asking you again,” Deku murmured.
Katsuki sighed and looked at him, brows furrowed and mouth scowling. “Did you meet some shitty ass bitch today?”
“ Huh ?”
“Did you!?”
“Kacchan, what are you talking about!?” Deku gaped.
“Stupid Ashido told me some upperclassman was looking for you,” Katsuki spat. “Who is it, huh? You fucking around with older fucks now? Your lame-ass pack not good enough for you?”
“That’s…” Deku furrowed his brows. “I… are you talking about Hinamori-senpai?”
“Do I look like I fucking know her name, dumbass?”
Deku sighed, rolling his eyes. He grabbed his comic book from the floor and tossed it uncaringly onto his desk.
“Well!?” Katsuki bristled, angry that his Omega — the one who was supposed to be his Fated Mate or whatever the fuck — was turning his back on him. He wanted to bite his nape and shove him face-first into the carpet, make him listen, make him bark.
“She’s a Support student, Kacchan. I helped her get her machines to her class, and, I dunno, she offered to make me something as thanks.”
“To make you something.”
“A hero support gear, Kacchan,” Deku added, huffing. “She said she was working on an enhanced glove and wanted me to have the prototype. I didn’t wanna accept it, at first—”
“As you shouldn’t.”
“—because I felt bad for taking it, but she insisted, and I accepted it.”
“She an Alpha?” Katsuki asked.
“Oh my God, is this why you’re freaking out?” Deku exclaimed, incredulous. “Kacchan, I barely know her! I literally don’t even know her first name!”
“Is she an Alpha , Deku?” Katsuki screamed, standing up.
“She is not, now get out of my nest!”
“How dare you kick your Alpha out!” Katsuki bared his teeth, snapping. “Shitty ass Omega, know your fucking place! If she were an Alpha, and you accepted a gift from her, that would’ve meant you were accepting a courting gift , you fucking dumbass!”
“I already told you she isn’t one, Kacchan! And— And so what if she were, can’t I receive some kindness from strangers without you blowing up in my face?”
“Why the fuck would you need that, huh? Am I not providing enough fucking kindness to you already that you need to get it from some random bitch!?”
“You sure aren’t being kind to me right now—” Deku suddenly put his hands on his chest and pushed , defiant, small Omegan fangs out, ready to pounce and bite and carry him out of his home. “—are you, Kacchan ?”
Katsuki’s thin patience snapped, and he tackled a snarling Deku onto the floor, tipping a chair over in the process and effectively making it fall right on Deku’s fucking face .
Deku yelped in pain. Katsuki, his previous anger now replaced by panic so abruptly that he almost got whiplash, hurriedly pushed the chair away and hovered over his mate. Deku was lying on his side, curled in on himself, whimpering, and covering his face with his hands.
“Deku…” The room was slowly becoming potent with the stench of anxiety — from who, Katsuki couldn’t tell. He whined and nosed at Deku’s unmoving hands. “Deku…?”
A sob.
His Alpha howled and kicked his heart with its hind legs. Katsuki whined again, low and long and apologetic, and nuzzled the side of his mate’s head, silently asking him to look at him. When that didn’t work, he started peppering kisses on his temple and neck. “I didn’t… mean to. Sorry, sorry, m’sorry. Omega, look at me, tell me where it hurts.”
Deku sniffled. “Go away…” He whispered behind his palms.
And those two simple words struck such a deep kind of hurt in Katsuki’s chest that he was momentarily too dumbfounded to move or speak. He just sat there, straddling his mate, frozen. He only moved when Deku started to push him off.
“Deku, fuck,” Katsuki said, small, on the floor and watching Deku move to his bed. “I didn’t mean to drop it on you.”
He crawled under his blanket and faced the wall, and when he spoke, it was muffled and tired. “The chair didn’t hurt me that much.”
“What?”
“Kacchan,” Deku said. “Just go. I have a study group thing later.”
A study group thing. Right. So, his friends were coming over, and Katsuki had to leave, because they weren’t open about their relationship with anyone despite being Fated Mates since they were in fucking middle school, because Deku had to get rid of his Alpha’s scent from his nest to avoid suspicion, and because Deku couldn’t stand him being there. Fuck.
“Fuck,” Katsuki said aloud, getting to his feet. “Fucking… fine. Whatever.” He grabbed his fallen things and went for the door, but he didn’t get out yet. He looked back at the lump in his mate’s bed, stinking with hurt and distress that Katsuki didn’t understand. A part of him — his Alpha instincts — wanted to slip in there and comfort him, but another part of him — him, the real, angry, difficult him — just wanted to leave and get his frustrations out with a punching bag, in peace. And, unsurprisingly to either of them, Katsuki chose the latter. Sighing, he turned around and closed the door behind him, cursing all the way to his room.
~0~0~
Katsuki was fourteen when he woke up to his first rut. His body was sweating, he was running a fever, and his mind was filled with luscious green and petrichor. “Deku,” his mouth moved involuntarily, like he was possessed, and fuck did he feel like he was. His body felt foreign, too wound up, ready to snap, his teeth more so as he bit into his pillow again and again, wishing it was a neck he could claim.
“Deku,” he spat again, but he wasn’t registering why he was saying his dumb classmate’s name — not yet. His mind was just racing with the nerd’s face, like a video in 3x speed. Some of them were memories — the times they spent together when they were five and Katsuki didn’t hate him yet, the time they went to the beach and Deku got scared by a crab, the time they had a sleepover in Katsuki’s room and Katsuki drooled all over the other’s hair — it was infuriating, because he buried these stupid memories years ago, and now they were resurfacing like the ocean waves of their last adventure together.
Then, it calmed, the images in his head slowed and slowed until it was normal speed. The next things that came to his mind didn’t feel like memories, because he didn’t recognize any of it. They were muddled and grey. They — him and Deku — were older and, and they were together and wrestling and— and not wrestling, but struggling, struggling to get clothes off, struggling to kiss each other, and—
Katsuki groaned and hid his face against his pillow, blood rushing to his face and to his crotch at the same time. His hand dived down the waistband of his shorts and boxers, desperately trying to extinguish the disgusting desire he felt for his Quirkless childhood friend — the Quirkless childhood friend he was disappointed in for not having a Quirk and failing to fill the spot next to him as a future hero and a worthy partner. But, it was useless, the Imprinting process was in motion and it wasn’t going to stop until it was done beating Midoriya Izuku’s face into Katsuki’s brain.
It was true now. Katsuki hadn’t wanted it to be true, had been scared of it since he first presented as an Alpha and Deku an Omega, since he first smelled petrichor and got such a violent tremor through his body that he had to physically beat it — Deku — down with his fist to make it go away, but now it was all true. His Alpha had Imprinted on Deku.
Katsuki whined as his hand went faster on his throbbing cock. His fever was spiking. He needed his Omega. He needed to hold him down and kiss him and breed him and provide for him, he needed to be a good Alpha for an Omega he hated and liked and who probably felt the same way about him.
His Alpha howled, or maybe he howled, when the thought of his Omega disliking him entered his frazzled mind.
He wanted to call him. He had his contact in his phone, he had it, he told everyone that he didn’t have it but he actually did and he didn’t know why he kept it, but it was there, he could call and tell Deku to come, tell Deku he liked him and that he was just too prideful and disappointed in his fate to say and act otherwise, it would be so easy—
Katsuki rolled over and toppled over the side of his bed, falling in a heap on the floor with his blanket tangled around his legs. He didn’t move to get up, just furiously jacked his knot faster. But, the images kept coming — Deku grown up, him grown up, nuzzling each other, biting each other, Deku’s hair splayed out on his pillow, breakfast together, fuck, so many and yet so unclear and blurry like a film under water, but it was fucking Deku in all of them.
Katsuki wanted to vomit. Wanted to scream. Wanted to cry because out of billions of people, he and Deku were somehow in the 5% who had Fated Mates, who had lifelong partners that would be with them in life and death and the next life and the next, the next, and the next. He and Deku — they were literally made for each other. Out of fucking billions, Katsuki was entertwined with Deku, the person he looked at the most often, the person who could give him a compliment and make his heart and head soar into the clouds, the person who knew him better than he ever wanted him to, and he couldn’t figure out if he was being punished or if he was the luckiest son of a bitch in the world.
Fuck, he was in pain now. The phone was out of his reach, and a part of him — rational, not yet consumed by the rut — was thankful that it was. He didn’t need Deku, he told himself, he didn’t fucking need him, but fuck did he want to. Wanted to hear Deku’s soft croons and whispers of love and adoration, just for him and no one else. No one else could have the privilege of having Deku’s attention but him.
Deku… Deku belonged to him. Deku was his, his, only his, only his to mark up and kiss and hold. And Katsuki was his.
The thought — it burned, it burned something frightening in his chest, something too unfamiliar for him to comprehend. But he didn’t want to comprehend anything, he just needed to get off, call in sick from school, and never see Deku again. Yeah, yeah , that would be good, that would be excruciating , but it was easy, easier than having to face Deku and tell him that what they had could change. Change was — impossible, he told himself. Change was impossible for them. They were always going to be Kacchan and Deku, two pathetic people with one broken relationship. They couldn’t be anything else. Katsuki didn’t know how to.
He was coming, he was going to come. “Deku,” he moaned. “Deku!” He shouted, and something inside him snapped — the images stopped, and his heart slowed down before it could break through his chest — and he came into his fist. He felt satisfied, almost relieved, because he thought he didn’t need Deku to get off, he could do this by himself. But then, the fever came again, and for three days, he was left useless and pining for someone he despised.
When he was better and ready to go back to school, he was surprised to see Inko and fucking Deku at the front door of his house. He looked at Deku, and Deku looked at him, face flushed like in his dreams, and Katsuki looked away. But, he was hyperfixating on the nerd, he knew, because he listened to how he took off his shoes, he kept his nose on alert for any sign of discomfort in Deku’s scent, even unconsciously sat next to him on the couch without their parents telling him to. He felt like he was going to go crazy.
They were calling in sick for another extra day. When he and Deku looked at each other again, Katsuki thought he might be for real, but somehow the tightness in his chest loosened and relaxed instead, as if his body knew that his mate was there. But, if anything, it made him feel sicker.
~0~0~
By 9 P.M., Katsuki still couldn’t sleep. Feeling calmer and more dejected than before he threw himself into his work out, he put on a hoodie and left his room for Deku’s. The hallways were empty, so he attracted no one’s attention when he gently knocked on his mate’s door. “Deku,” he murmured. After a second, he knocked again. “Deku,” he said again, more insistent.
There were footsteps from the other side, and then the sound of a lock. Katsuki waited three seconds before he turned the handle and pushed the door open slowly. He was holding his breath for some reason, but when he stepped into the room and closed the door behind him silently, he gasped and inhaled. Burnt wood winded through his nose and squeezed his chest like transparent wire, different from its natural rain forest scent but at the same time the usual scent that Katsuki kept smelling whenever they were together. Katsuki scrunched his nose at it.
Deku was sitting on his bed, not really looking at him but not facing away from him either. A thick, orange blanket wrapped around him; Katsuki’s first courting gift from a couple years ago. His chest puffed out a little more at the sight, at the knowledge that his Deku still had it and was choosing to have the item around him despite… how they were.
Katsuki sat on the edge of the bed slowly, his eyes never leaving Deku’s face. It was only after he brought his legs up on the mattress did his green eyes flick to him.
“Hey,” he greeted lamely. He cleared his throat and tried again. “How was the, uh, study thing?”
Deku shrugged. “Fine.”
He paused. “You don’t have a broken nose, so are you, like, okay?”
At that, Deku let out a quiet huff, almost like a laugh. “I told you, the chair didn’t really hurt me,” he said. “M’fine.”
Katsuki stared at him. Tentatively, he scooted back until his back was flush to the wall, a feet away from his small, strong mate. Deku’s hand came up to scratch the skin around his collar, and Katsuki’s eyes followed the motion intently.
“You haven’t taken that thing off yet?”
“No.”
“Don’t you want to? S’just me now.”
Deku opened his mouth, but no words came out. After a second, he closed it, and shrugged. He reached behind him for the clasp, and after a soft click, the collar was loose, discarded to the side. Katsuki took in a lungful of Deku’s uninhibited scent, not caring that it still tasted bitter on his tongue because this was his fucking mate’s scent nonetheless, and it still made him drunk, made him lose his goddamn mind. When he opened his eyes — when did he close his eyes in bliss like that, fuck — he saw the smooth, unclaimed skin of Deku’s scent gland. Katsuki’s mouth watered at the sight, but he swallowed the venom dripping from his fangs, and turned his head to face forward.
“I’m not cheating on you, Kacchan.”
Katsuki whipped his head, stunned, and Deku met his gaze head-on — still cocooned in his safe blanket. When Deku didn’t elaborate any further, Katsuki sighed slowly from his nose. There were a lot of things he wanted to say to that, or around that, or around the way Deku was sinking into his colors like there was no other ocean he wanted to drown in. Who is she, Deku? Why’d you help her? Why do you never let me carry your books for you, the way you did for her? If I helped some bitch with her machines or books or whatever the fuck else, would you feel this way too? Are you ashamed of our relationship? Is that why Ashido and everyone else treat this shit like some stupid gossip and not something as fucking rare as Fated Mates, as us?
Katsuki opened his big mouth, but when Deku straightened his back and looked at him more seriously, the thing he said instead was, “I’d bite her head off if you were.”
Deku blinked, then looked away, sighing, and Katsuki internally cursed at himself.
“I know you aren’t,” Katsuki tried to lessen the damage. A lot of times, it felt more like putting gasoline on fire. “I didn’t mean to hurt you. It was a fucking accident, I swear.”
“For the last time, Kacchan, the chair didn’t hurt me,” Deku suddenly groused. “It was— Oh my God, forget it.”
“What?” Katsuki demanded.
“You hurt me by accusing me of cheating, you oblivious Alpha!”
“And I just told you that I know you didn’t, so what more do you want from me?” Katsuki’s Alpha was pacing inside the confines of his ribcage, wanting to thrash and bite and howl, confused, agitated for not knowing what to do to make his mate fucking happy.
Deku let out a long groan against his blanket, dropping himself on the bed, shutting his Alpha out.
Katsuki wanted to whine, get his mate to fucking tell him what he wanted, what he was doing wrong, but he grit his teeth and held the degrading noise at bay. However, he didn’t walk away. His ass was still glued to the Omega’s bed. He was too stubborn to ask the things he wanted to know, but he knew leaving wasn’t going to do them much good, either. He didn’t want his mate to cry, dammit.
After a minute of stifling silence, Katsuki decided to say, “I thought you left this blanket at home.” Because he had no idea what else to say that wouldn’t make either of them upset.
Deku peeled his blanket away just enough for an emerald eye to peek at him. Almost shyly. “Of course not,” he started, hushed, like it was a secret. It was, though. Nobody, not even their pack, knew that they were dating. Too complicated, for both of them, too. This, this was too intimate and too important for the world to know, yet. “You gave me this. It’s the only… only thing I have of you. Like, I mean, for my nest.”
“Mm.” He paused. “Do you, like… is it enough?”
Deku shrugged. “Normally, sure. I see you every day so it’s not like I’m not getting enough of your scent. But it’s, um, not— not enough, I guess, when I have my— my heat. I can’t smell you as much.”
“We have sex,” Katsuki found himself saying automatically, causing both of them to blush and avoid eye contact.
“I-I-I know we have sex , Kacchan,” Deku stammered after his initial embarrassment subsided. “I meant— before that. I— I nest. I’m talking about nesting . It’s not enough when I nest, I don’t have enough of your clothes to properly smell you.”
“O-Oh.”
“Yeah.”
“You didn’t tell me that.”
Deku looked at him, then looked away again. Katsuki didn’t like that, but he held himself back from taking his chin in his hand and forcing him to look — pay attention to me, dammit.
“I didn’t think it mattered,” Deku eventually said.
“Dumbass Omega.” Katsuki clicked his tongue before stripping off his hoodie and tossing it at Deku’s bewildered face. “Here. Take it, keep it in your nest or whatever. Fuck.”
Deku sat up, eyes twinkling. There we go. “What— Really?”
“Take it.”
When Deku gently held the black garment in his hands, his eyes glazed over, almost like he was getting high, and he purred and buried his nose in the center of the hoodie. Like a bubble popping, the room was becoming thick with the scent of a content Omega, and Katsuki blushed madly. His chest expanded to make room for his beating heart. His thoughts were pushed to the side, and all that was left was “My Omega is beautiful like this”.
Katsuki leaned in and kissed the top of Deku’s curls, to which the latter hummed happily and kissed the side of his neck. Deku giggled softly against his skin, and Katsuki curled his arm around his to keep him there.
“I can stay the night, if you want, or whatever.”
“Mm. Please stay, Kacchan.” Deku brought him in for a sweet kiss, melting him from the inside. His Alpha wagged its tail as they tangled their arms and legs with each other on the bed, solid and safe, together still.
Finally, Katsuki could sleep peacefully.
And when the next morning approached, Katsuki slipped out of his mate’s arms, ignoring his sleepy whine, and continued their day as nothing more than rivals once again. Because, as far as the world knew, they were incompatible and were not in love.
… Katsuki and Deku were in love.
~0~0~
At first, Katsuki didn’t want to believe it — that he was in love. When he had his first rut, Deku had also had his first heat. Great, the first thing that they got in sync was their fucking cycles. But, anyway, Deku blabbed to his mom like the fucking momma’s boy that he was. “Mom, Kacchan’s my Fated Mate! Why does the world hate me, Mom?” Was how Katsuki thought Deku broke the news to her. Inko called his mom, and his mom scolded him for not telling her when she’d been the one to keep him fucking alive through his rut and that she had to find out from her fucking neighbor slash soon-to-be-sister-in-law. It was a shitshow.
And then there was Deku. He was… quiet. A contrast to his mile-a-minute thoughts. When they had that first talk in the living room with their parents, Deku was silent for most of it. He was wearing his scent blockers, so Katsuki couldn’t tell what he was feeling underneath those baggy clothes and skin. Not that it would’ve mattered. He wouldn’t have known what to do either way.
Then, school came. They had to go back. They couldn’t stay in the shelter of their rooms forever. They didn’t really talk a whole lot normally, and to other people, they were probably acting the part just fine, but Katsuki knew better. He was stiff — they were stiff. The silence was a force weighing down on their shoulders. Deku hadn’t spoken a word to him in days, since before their Imprinting happened. He absolutely hated it. His Alpha was in pain from the blatant neglect. Want to please Omega. Want Omega to love Alpha.
Ridiculous.
But it came to a head on a simple Friday, a little over a week after their Imprinting. It was P.E., and Katsuki needed to get some water to cool his head. He was going to the water fountain when he saw Deku with two of their classmates at the far corner of the building.
His heart skipped a beat. Then, one of them grabbed Deku’s arm and twisted , making Deku yell out sharply, and Katsuki’s vision went red.
For the first time in his life, he was suspended from school. He’d broken the guy’s nose and knocked his fang and two front teeth out of his mouth. The other guy had tried to intervene, and Katsuki had broken his arm. Katsuki wanted to think he wasn’t expelled on the spot because he’d explained that they were bullying Deku and that he was trying to protect the Quirkless Omega, but from the way the principal barely spared a glance at Deku’s fidgeting form, Katsuki knew that it was just because he had a perfect track record, and it would be a waste to kick him out.
His mom screamed the whole time — not at him, she was actually fucking proud that her son stuck up for his mate (the term made him flinch, but it didn’t anymore now) as he should as an Alpha, but at the principal for having the audacity to punish Katsuki at all. Inko was, fuck, listen, Katsuki didn’t know Inko too well, but when she went all out on the two fuckers’ parents that day, Katsuki knew that he couldn’t afford to fail to be a proper Alpha to her son.
In the midst of that not-so-simple Friday, after the chaos at school was all said and done, Deku pulled him aside before they went home. “Kacchan…” He said, and fuck Katsuki missed his voice. “Um. Thank you. You didn’t have to do that.”
“Don’t be stupid, Deku.”
“I-I got you suspended—”
“Wrong.” Katsuki faced him, heart hammering, palms threatening to pop. “You— You didn’t do shit. I got suspended because the fucking principal’s a douche.”
“You didn’t have to defend me.”
“I…” Katsuki bit his lip. “W-Wrong. Again, fucking nerd. I’m— I’m your Alpha or whatever. It’s my job to defend you. Dumbass.”
And it was as if a leech was finally removed from his flesh, and he didn’t feel so tight in his own skin anymore. Deku was looking at him with glistening eyes so wide he could drown in the meadow of his irises.
“If you’re… umm. I can’t— I don’t know. How. To do this fucking shit. After, you know. After us, the us from before this whole shit started. I don’t fucking know how this is supposed to work.”
“Kacchan…” Deku stepped closer, the wonder, admiration, and disbelief still painting the colors going through his eyes. “I don’t either, but… maybe it can work? I’d… like to give it a try. If you want.”
And by God did he want, wanted Deku’s shyness, unease, doubt, and later his toughness and conviction, wanted to try it all. More than anything, he wanted to fucking bury his shame and pride to make room for all these things. He hadn’t quite figured out how to, and they had to do a lot of maneuvering for the first months, but there was space now. And Deku took up all the space he could.
But there was old junk in there still, cluttering around his Omega like a cage. He didn’t know where to put it yet, or how to throw it away. He knew that there should be a chute or a door or something to get it all out, but he had yet to find it. While his Omega was growing bigger in his life, the space was starting to get cramped. He could only organize shit so many times before it would all collapse over their heads.
~0~0~
Todoroki Shouto was a threat. It started out as being an opponent for the number one hero spot in the rankings, but then it became much deeper.
Fucking Todoroki liked Deku.
Katsuki had suspected it for a while. It started during the sports festival when Todoroki pulled Deku aside to have a private conversation, which Katsuki followed because he had to take care of his fucking mate. The thought of another Alpha taking what was his enraged him, and when the bastard threw the match, it made him go absolutely feral. How dare this extra spit at his fucking Alpha like that!
After the festival, Katsuki had told Deku of his suspicions, but Deku didn’t take him seriously. “He’s just a friend, Kacchan,” Deku told him, frowning. “And even if he feels that way about me, I’m never going to be interested. I’m with you, aren’t I?”
Yeah, he was, but nobody else — his fucking ma and pops didn’t count — knew that. Todoroki didn’t know that he was taken.
But then, oh fuck , Katsuki saw it happen. It was the day before their provisional licence exams. Everyone was nervous about it. Katsuki thought it wouldn’t be any harder than fighting actual villains, so he wasn’t as jittery as the rest. He noticed that Deku kind of was, though. He was with his pack on the couch, eating, bonding or whatever to keep their spirits high. Katsuki was lounging on another couch parallel to them, scrolling idly through his phone.
“How’re you feeling, Midoriya?” Todoroki whispered to Deku. He thought he was fucking slick, but Katsuki could hear him still. He didn’t look up when Todoroki continued. “Are you still nervous?”
“Ah, no, not as much anymore.” Deku shot him a grateful smile. Katsuki held back an eye roll. “I guess it’s not really about tomorrow, but also a lot of things. Like, tomorrow’s pretty daunting, sure, but there’s all these new things happening to us, too! It’s all just new.”
“Hmm. Are you homesick?”
“A little.”
Todoroki paused, then he shifted so his thigh touched Deku’s. Katsuki bristled, but Deku crossed his legs so he wasn’t touching him anymore. Okay. Okay, good. His Alpha put away its fangs, but its fur was still standing up, ready.
“May I offer some of my clothes for your nest? Maybe they can help you adapt to the dorms better.”
Oh, ohhhh, now he was just asking for death, he was just begging for his throat to be ripped out, and with Katsuki right there, he was fucking just —
“T-Todoroki-kun, that’s— that’s sweet of you—” Sweet? What!? “—b-but, no, thank you. That’s not how it works either way.” Deku laughed curtly. Why the fuck was this fucker laughing for him? Why wasn’t he clawing his eyes out for fucking attempting to step into his safe place? “You see, even if I was homesick, an unfamiliar scent would just make it worse. I’d need something from home, like, maybe my mom’s scent, or my old blanket, things like that. Another person’s clothes in my nest would just agitate me.”
“Oh.” Todoroki blinked. Katsuki resisted the urge to hurl his phone at his head. “Okay, I apologize. I’m not too familiar with these things.”
“That’s okay, Todoroki-kun!”
“Well, if not for your homesickness, maybe you’d want to accept my clothes for something else?”
“Something else?”
“For courting, Midoriya.”
Deku blinked at the same time Katsuki’s Alpha broke down its barriers and roared. “I’m gonna fucking kill you !” Katsuki jumped over the coffee table and tackled a shocked Todoroki to the ground. There were people screaming, but Katsuki didn’t care. He was landing punches after punches, drawing blood, before fucking Todoroki used his Quirk, the fucking cheater, and froze his fist in place. Katsuki yelled and used his explosion to break the ice, but the pause gave Todoroki enough time to regain control and flip their positions. He landed some dirty punches before Katsuki pulled back his arm and prepared an explosion.
But the bomb didn’t detonate. His palm sparked, then died. Katsuki cursed. Todoroki smirked, and punched the fuck outta his nose, right before someone hauled him off him. “Fuck!” He cursed, holding his bleeding nose in his hand. Another person was grabbing him from under his armpits, pulling him up to sit, but Katsuki elbowed them away and glared at a panting, equally bleeding Todoroki. Good, he thought, grinning, feral.
“Really?” Aizawa’s annoyed voice boomed. “Right before the provisional— Okay, you know what, show up to the exam with a broken nose. I don’t give a damn. You, the rest of you, up to your rooms, now ! Leave the both of them. If they can pick a fight with each other, they can patch themselves up on their own.”
“A-Aizawa-sensei—”
“Midoriya, I mean it, up stairs. I’m not dealing with this before I’ve had my morning coffee.”
The others slowly left for the stairs and elevators, albeit reluctantly, but no one was going to argue with their teacher. Todoroki sent a glare his way, and Katsuki in turn sneered and growled back. Todoroki went for the elevators — the motherfucker — and Katsuki went for the stairs. He was still foaming at the mouth when he entered his room, and was barely surprised to see Deku inside. The Omega already had a first aid kit in his hand, but his eyes were angry, his forest fire scent suffocating.
“What the hell was that, Kacchan?” Deku asked, voice deceptively calm.
Katsuki stared at him for a second before slamming his door shut and taking off his blood-stained shirt.
“Why do you always pick fights with my pack?”
“I don’t.” Katsuki threw his shirt aside and sat on the bed. A heartbeat passed before Deku joined him and opened the kit. He withheld a wince when his mate dabbed at his nose a bit too aggressively.
“You do , and it’s driving me insane, Kacchan! You’re my Fated Mate, and I love you, but they’re my pack! Why can’t you get along with them? Why can’t you even try?”
“Oh, so I’m the asshole today?” Katsuki slapped his wrist away. “Fuck you, Deku! Fucking Todoroki tried to get in your pants—”
“He—”
“He was trying to court you, you useless Omega! And you expect me to not be mad? What the hell is that? Wouldn’t you feel pissed if some Omega threw themselves at me?”
“You took it too far! Plus, Todoroki doesn’t even know we’re dating. It’s not his fault.”
“Oh my fucking God, you’re defending him, you’re actually defending him over me. You wanna sleep with him, Deku? Huh? You wanna invite him over for your next heat? Where’s your calendar, I’ll fucking mark it there myself if you’re so adamant on fucking another Alpha, you two-timing slutty ass son of a—”
“Shut up ! Shut up, Kacchan, shut the fuck up, how dare you call me that! How dare you even insinuate —”
“You know he’s into you, and you still insist on keeping him around you! You’re cheating on me, Deku! Just say you wanna sleep with him and replace me!”
“I turned him down, you stupid Alpha! Did you not see that, or were you too doped up with your Alpha hormones? Todoroki is my friend , and I would’ve explained to him that I—”
“Explained what, huh? That you’re with me?”
“Oh, well, I don’t know, Kacchan, maybe if you weren’t so ashamed of our relationship—”
“What the fuck !?”
“—or maybe if you didn’t interfere and let me speak for myself, I would’ve! I don’t know, Kacchan, because you never gave me the chance to! You always think the worst of me, that I’m cheating or backstabbing you or replacing you or whatever else and I don’t know if you’re ever going to think differently!”
“That’s—” Katsuki huffed, almost laughing to himself, because this was bullshit. It was bullshit. “That’s stupid.”
Deku was breathing heavily. At some point, they had stood up and were facing each other with fangs out and hearts barely swelling past their outer skins. Katsuki’s nose had stopped bleeding by this point, but the dried blood was choking him. At least, he thought it was the blood, until he felt his eyes start to blur and water.
Deku exhaled shakily. “Do you think I’m a good mate?”
“You know I love you.”
“No,” he said. “That’s not what I’m asking. Do you think I’m a good mate? For you?”
At this, Katsuki finally laughed, short and booming. “What the fuck?” He wheezed. “That’s a stupid question. We’re Fated Mates, you dumbass! We’re literally made to be each other’s mates.”
“Exactly.” Deku hiccuped, and then his tears finally escaped his lashes, and he was crying fully. He sniffled and ran the sleeve of his hoodie — his hoodie, Katsuki’s hoodie, he was wearing the hoodie he gave him — over his eyes, but he couldn’t bank the flood any longer. “Then w-why— Why do you always think I’m not good, Kacchan?”
Katsuki stopped and gaped. When the silence stretched on for another second, he huffed a laugh, because he wasn’t used to being speechless. He huffed another laugh when he racked his loud ass brain for a response and came out with nothing.
“Kacchan?”
“Fuck, Deku, what…” Katsuki raked his hand through his hair, almost breaking skin from how his nails were digging in his scalp. “I don’t.”
“You do,” Deku whispered. “You always assume I’m gonna do something bad or betray you in some way. You don’t trust me.”
“I do trust you, what the fuck.”
“You trust me with your life, but you don’t trust me with our relationship.”
Again, he was speechless, so he huffed another laugh and sat down on his bed, but when he sat down, something wet fell on his pants, and it took him a second to realize that he was crying fat, ugly tears. He hurriedly wiped them away, as if he could erase them along with Deku’s shitty ass words. Words that he wanted to say weren’t true, but couldn’t.
And Deku sensed that, his hesitation, and he nodded solemnly. “I don’t know if I can be with an Alpha like that.”
“I’m a good Alpha,” Katsuki still tried, because he was a fighter and he didn’t want to lose Deku even though he knew he was gripping sand between his fingers.
Deku paused, frowned deeper, and murmured, “But not to me.” Deku slammed the first aid kit shut, but even that couldn’t drown out the sound of Katsuki’s Alpha howling and whimpering in agony. Katsuki clutched his chest and doubled over, the wind knocked out of him, but Deku was getting up and leaving, and when he went out the door, he didn’t come back for his idiot Alpha lying pathetically on the ground.
~0~0~
It was the week after their Imprinting all over again. They ceased to talk, but the world didn’t question it, because, as far as the world knew, they were incompatible and were not in love. Yeah, they were incompatible, but they were fucking in love, goddammit. Katsuki loved the stupid nerd, always did, always felt his heart soften each time Deku fell asleep on him after a quiet study date, always felt his palms sweat dangerously when they held hands behind their backs, always found adrenaline when they had sex in their parents’ houses. Katsuki loved him. But that didn’t matter. He didn’t understand him.
He flunked the exam with Todoroki. He felt emasculated, he felt inferior, he felt empty and lonely without Deku, and he felt like this was somehow his punishment for ending All Might and his bullying and his everything, and he couldn’t take it. He couldn’t keep maneuvering and rearranging his mental shit anymore — there was no more room. He had to get all this out before he broke like a shipwreck.
After days of not talking to his mate, he finally approached him, and brought him out to fight at Ground Beta.
~0~0~
“I love you, but I hated you before I loved you. And I think I haven’t fully gotten rid of that hate yet. It’s just— there. I love you but I think I still hate you a little, but I don’t wanna hate you, I fucking love you.” Katsuki sent a blast Deku’s way, but his mate dodged it expertly.
“I know you do, I know you love me. I love you, too.”
“I don’t wanna hate you.”
“I know you don’t.”
When Deku slowed down his punches, Katsuki yelled and grabbed him, aiming for a punch, but Deku held up his arms and headbutted him. It hurt like hell. It felt good.
~0~0~
They brought down a building. It was debris at their feet now.
“I accuse you of cheating because I can’t handle that you’re so fucking good to me when all I did was hurt you back then. It’s surreal. Nobody’s that nice.”
“You’re good to me, too. You weren’t back then, but you’ve changed. You cook for me. You keep your door open for me in case I have a nightmare and I want to sleep next to you. You push me to be better.”
“That’s only because I found out you were my Fated Mate, and I was, I don’t know, given the green light to accept my feelings for you or something.”
“But you didn’t go for it. Not completely. Because you were confused on how to move forward.”
“Yeah.”
“If it makes you feel any better, I’m not that nice, either. I show people your ugly kid pictures sometimes.”
“You motherfucker!”
There was an explosion, followed by a hearty laugh.
~0~0~
“Todoroki’s my pack, and he will always be even if you hate him. But I don’t and will not ever hesitate to kick him in the balls if he ever tries to come between me and you. You’re important to me, but I need you to let me choose who else gets to be important to me, too.”
“Fine. But, if after you tell him you’re not on the market, and he keeps insisting, I get to beat his ass.”
“Fine. I know he won’t, because he’s not that type of Alpha—”
“How would you know!?”
“Shut up, Kacchan, it’s my turn to vent!”
“Fuck y— FUCK YOU BITCH, DON’T HURL A GODDAMN LIGHTPOST AT ME!”
“Catch this Detroit Smash, Kacchan!”
Katsuki caught it, and he was knocked back against a wall.
“Okay, you got a good punch in.”
“You good?”
“Yeah, yeah, don’t treat me like I’m a pup. Continue your goddamn vent.”
“Okay. Thanks. So, as I was saying…”
~0~0~
“I wish you were more honest.”
“Me, too.”
“I wish you’d bitch at me and tell me what you want instead of clamming up for the sake of, I don’t know, whatever it is you think you’re doing.”
“I don’t wanna be a burden to Kacchan.”
He dodged another blast.
“But I guess… that backfired. For the both of us.”
“Yeah, no shit. Heads-up, that roof’s gonna slide off and knock you dead. Come over to this side.”
“Don’t hit me.”
“Just get over here before it falls, fuck!”
~0~0~
He was finally crying. “Why did I become the reason for All Might’s End!?”
For the first time since they started fighting, Deku flinched.
~0~0~
They got caught by Aizawa. The old man looked ready to kill them and then himself. They got away with cleaning duty.
~0~0~
“Hey, Deku?”
Deku hummed, in the middle of vacuuming. Katsuki wrung his wet rag nervously.
“Thanks. For taking me back, or whatever.”
“Oh, Kacchan, I didn’t break up with you, I promise. I could never.” Deku walked over and kissed his cheek, but realization struck him, and he looked frantically around for any spectators. “Oh— Oh my God, I’m so sorry, I wasn’t thinking—”
“Stop. Let them know. I don’t care.”
“You… You don’t?”
“Mm.”
“You’re okay with people knowing about us?”
“If it gets extras like Todoroki and Hinamori to back off, yeah, whatever. I’ll… tell my pack. You tell yours. The news’ll spread after that. But, fuck, if you don’t want to or whatever, that’s fine, I don’t—” Deku kissed him full on the mouth, moaning , his scent bursting with flowers and morning dew. Katsuki grunted when he pulled, dropped his cleaning supplies when he purred and licked at his teeth. He grabbed his hips and pulled him closer, pushed him back until he was flushed against the window he was trying to goddamn clean. Deku giggled against his mouth. Katsuki grabbed the back of his head and devoured the sweet noise.
“Kacchan,” Deku gasped, pausing to moan when Katsuki latched onto his jaw. “K-Kacchan, yes, yes , I want them to know, finally, finally, b-but I don’t think— ahh— I don’t think exhibitionism is the way to do that.”
“Yeah, shit, can’t, can’t let them see you like that. Where, hah, yours or mine? Fuck it, yours, yours is closer.”
“O-Okay!” Deku laughed breathlessly as he was pulled to the stairs, their chores dropped and forgotten on the floor, much like their clothes when they finally locked the door behind them.
Deku was still laughing when he fell on the bed, naked, and Katsuki ate that shit up — literally. He kissed him anywhere and everywhere he could — his mouth, his cheeks, his neck, his nipples. Deku sang for him at each spot.
“Alpha, m-my good Alpha, mine, I— please? Please, please—”
“Remember what I told you, Deku?” Katsuki whispered in his ear, teasing. “Tell me what you want. C’mon, don’t clam up, tell me what you want.”
Deku huffed, annoyed, but he was soon whining for it when Katsuki licked his scent gland. “Be inside, please, be inside me, and claim me.”
“What?”
“Claim me.” Deku met his bewilderment with a shy grin. “That’s… what I want. Is that okay? Do you want to?”
“I—” He felt like he was in the desert, lost without a map, parched, hot all over. He gulped and mouthed at his mate’s ear. “Fuck, I— You’re fucking perfect, fuck , why would I not, why would I not want to.” He was babbling now, crying a little, too, but it was overwhelming him in the best of ways. His mind wasn’t bursting at the seams anymore, but instead was ready to take up more and more of Midoriya Izuku and make more room for him at the same time, and he was about to have this boy all to himself forever. That was scary, but he wasn’t fourteen anymore. He was ready to face that fear now, with Deku.
The Omega cried when he entered two fingers inside his slick hole, gripping him so tight as if Katsuki could ever think to leave. When he got to three fingers, he gently crooned to ease his Omega, and when he pulled his hand away and lined his cock to his hole, he rumbled and gripped his hips. He slowly pushed in, and watched his pretty Omega whine and grip and bite his orange blanket.
“Ahhh, K-Kacch— Kacchan, fuck, fuck, I-I love you, I love you, my big dumb Alpha, my good Alpha, love you so much.”
Katsuki groaned as he bottomed out, inhaled deeply, and started snapping his hips at a steady pace. Deku hiccuped and reached his arms out for him, and Katsuki gladly succumbed to his heat. He fucked him faster, matching their labored breaths and desperate calls.
“Bite me,” Deku cried, the cliff hanging at the edge of their vision. “Bite me, Kacchan, and never let me go again.”
He was a goner — if Deku’d asked him to burn the world to the ground, he would’ve done it in a heartbeat; if he asked him to love him forever, he’d commit every breath, every fiber, every atom he had to him, because he knew his beloved would fill his empty vessel with his own breaths, fibers, and atoms. He would never be inferior if he had Deku building him up with his own parts every day.
When his knot finally popped into place, Katsuki curled over his mate and bit down on his scent gland. Deku screamed in pure bliss, and Katsuki fell into his orgasm like a man without a parachute. He rode out the high, the bond, and he didn’t stop until his mate started to whimper and slap his back. Katsuki slowly removed his bloody mouth from his neck, wincing when he saw how deep he’d accidentally bitten him.
“Sorry,” he murmured sheepishly.
“Are you kidding?” Deku huffed, smiling drunkenly. “That was the best sex ever. I think I saw God when I came.”
“God wasn’t the one fucking your brains out. You saw me , you dumb shit.”
“Yeah, yeah.”
“So.” He coughed, suddenly feeling awkward with his knot buried in his ass and teeth coated in blood. “We tellin’ them tonight?”
“Sure! I’d like that. I’ve wanted people to know for awhile.”
“Mm. And, so, I bit you. When are you gonna bite me?”
“Oh God, later, later, I can’t even feel my jaw right now.”
“How later? You’d better not be—”
“Kacchan.”
“I'm pulling your leg, nerd.” Katsuki kissed his cheek, chuckling at Deku’s petulant pout. “Yeah, I know you’ll claim me sooner or later. Can’t expect you to resist all this for too long, after all.”
“I regret everything. Unbite me right now so I can leave you for Kaminari.”
“No can do. You’re stuck with me forever.” He kissed his lips, and he felt Deku smile and sigh into the bloody kiss. “I’m giving you forever, so I expect you to do the same.”
“Yeah, yeah.” Deku giggled and looped his arms around his neck. “Bossy Alpha.”
“Your Alpha, though.”
“Mm.” He kissed him again, his grin vast and contagious. “I love you.”
“I love you, too. More and more.”