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It takes less than a minute for Megumi to realize what's happening to him.
He's been in heat before, plenty of times after all these years. He knows the feeling too well. The way his body grows warm and his head grows cloudy, his hands starting to shake as his stomach pools with heat. He's familiar with the way slick starts to drip between his inner thighs as his breaths come faster and faster, and soon he has no choice but to retreat to his nest and pleasure himself, even if his own hands will never be enough. Never what he truly desires.
But usually, Megumi has time. Usually, he feels those preheat symptoms days in advance, giving him plenty of time to prepare. He calls off classes. He gets a hotel room, far away from campus. He builds his nest. And by the time his heat hits, he's comfortable, safe, and ready.
But this time, everything has gone awry.
Megumi did not feel those preheat symptoms. He did not have time to tell his professors he would miss, or to find a hotel room, or to build his nest. Instead, he finds himself standing in the middle of his dorm room, slick dripping into his underwear as his heat washes over him dangerously fast.
His dorm room, with an alpha living right next door.
I'm so fucked, Megumi thinks. And then the waves of heat drag him under, and he thinks nothing at all.
***
There's a scent coming through the wall.
“Do you smell that?” Sukuna asks.
Itadori grumbles, slapping his hand over the mouth on his cheek. “Shut up. I don't smell anything.”
Sukuna goes quiet for a moment, even though it pains him to be so cooperative. But he's focusing. Focusing on the scent most definitely drifting through these flimsy dorm walls and beneath the door. The scent that is sweet and heavy and strong—familiar, but stronger than Sukuna has smelled it before. It takes him a moment to place it, but when he does, satisfaction and anticipation flood his system.
Because that scent may be sweeter and stronger than Sukuna has smelled it, but he knows exactly where it's coming from. He's smelled a lighter version of it before. Countless times, to be exact.
“Fushiguro is going into heat,” he declares smugly.
Itadori’s posture tightens. “No he's not. Fushiguro never goes into heat here. He always goes to a hotel.”
“My senses do not deceive me, brat,” Sukuna snaps. “I know an omega in heat when I smell one.”
Itadori freezes and says nothing for several seconds. He sniffs the air, his posture tightening even more. Sukuna can tell that he's smelling it too—after all, Itadori is an alpha. A pathetic one, but an alpha all the same. He should be able to recognize an omega in heat by nose alone, and he does, Sukuna realizes. His posture tightens more, hands squeezing into fists in his lap where he sits on the bed.
Itadori Yuuji may pretend to be composed, but he's just as affected as any alpha would be by that heady scent of an omega just waiting to be taken.
Just as affected as Sukuna is.
It's been a long while since Sukuna has smelled something so delicious. So desirable. And the fact that it's coming from Fushiguro Megumi? From someone so delightfully interesting and uncommonly appealing? Well, that just makes it all the better.
And Sukuna just has to have him.
“You should switch with me,” Sukuna says suddenly.
“What?” Itadori exclaims. “I'm not going to do that. Why the fuck would I—”
“Are you planning to go in there and do what needs to be done?”
Itadori freezes. “There's nothing that needs to be done. Fushiguro is fine on his own. He doesn't need anything from me.”
“Ah, maybe not from you,” Sukuna taunts.
It takes Itadori—stupid brat that he is—several seconds to make sense of Sukuna’s words.
“Hey, no,” he whines. “We're not doing that. Not a chance in—”
“And why not?” Sukuna interrupts. “Don't you know how difficult a heat can be? Don't you want your dearest friend to be comfortable? Think, Itadori. He would thank you. He would be grateful.”
Itadori pauses again. Sukuna can tell he's starting to crack.
So, so easy to break.
“Well, maybe I could—”
Anger rips through Sukuna.
“You will do no such thing.”
Just the idea of Itadori’s hands on Megumi’s skin is enough to have Sukuna growling. That boy—that omega—is his. His alone. Sukuna wants no other alpha to knot or breed such a perfect specimen. Hasn't Sukuna known all along that Megumi was built for him? Him, not this overgrown puppy.
“Wait,” Itadori says, “you want to—”
“I will,” Sukuna interrupts him again. “I take what is mine. Always."
“Hey, Fushiguro isn't yours. He isn't anyone's.”
Sukuna nearly laughs. Itadori hasn't a clue what he's talking about.
“Switch with me,” Sukuna repeats.
“No.”
“Yes, brat.”
“No, asshole.”
Sukuna grinds his teeth. He hates this stupid arrangement. He hates not having full control. If he did, he would be in there already, fucking Megumi into the mattress. Not arguing with a child.
“I will make a deal with you,” Sukuna finally relents. When Itadori doesn't reply, he continues. “What do you require to give me what I want?”
Itadori goes silent while he thinks. Finally, he squeaks out, “It’ll help him? You think?”
“I know.”
Itadori pauses once more. “You… You can't force yourself on him. If he says no, you leave him alone. He gets a choice.”
Sukuna nearly laughs again. Little Itadori is so clueless. Doesn't he know how omegas are in heat? Doesn't he know that Megumi will have no choice? His inner omega will respond so perfectly to Sukuna’s alpha, and he will need him, just as thoroughly as Sukuna needs Megumi.
But Sukuna will play along.
“Alright,” Sukuna replies politely. “I will not force myself on him.”
“You'll be gentle with him. You will not hurt him.”
Sukuna’s mouth draws up in a smirk. “Unless he asks for it.”
“He won't.”
“Ah, we'll see.”
Itadori pauses once again. “And you have to be more fucking cooperative. Less mouthy. Do what I say.”
“I will not—”
“I am letting you use my body to fuck my best friend. I get something out of it.”
Sukuna grinds his teeth again. He so hates to be stifled. But Megumi’s scent is growing stronger through the wall, and Sukuna is beginning to feel desperate. He will knot that omega. He will breed him. Fushiguro Megumi will be Ryoumen Sukuna’s.
“Fine,” he spits. “I agree to your terms.”
“Alright.” Itadori nods. “Let's do this.”
The change is subtle, like it always is. Seconds pass, and before Sukuna knows it, his world has sharpened. He has a different perspective. He feels power surge through his bloodstream as he wiggles his fingers and toes, and they move on his own command.
Sukuna smiles. Now the fun begins.
***
Megumi has no clue what he's doing. His head is full of clouds. He can't focus on a damn thing except the way his fingers feel inside himself, stretching him out perfectly but not enough. Never enough. No amount of his own fingers or toys will ever perfectly replicate an alpha’s knot, and Megumi feels empty without one.
But still, his fingers are better than nothing as he fucks them in and out, breathy moans leaving his lips when he crooks them just right. He'll need more soon—a toy, at least. The clouds are getting heavier and thicker, his heat starting to hit at its absolute fullest, and Megumi feels feral. He feels desperate. He feels—
“Hello, little sorcerer.”
Megumi rips his hand from his own body, eyes shooting towards the door. The door, that he clearly didn't fucking lock. Like an idiot with a death wish.
For a second, Megumi sees the intruder and thinks that it's Itadori. But then he realizes that he's incorrect. There's markings marring Itadori's skin, and a smile on his face that is unlike any that Megumi has ever seen him wear. And his scent is different, Megumi realizes. Subtle, but not quite the same.
No, it's definitely not Itadori. It's someone else, wearing his skin.
“What are you doing here, Sukuna?”
The words come out breathy and strained, not forceful like Megumi intended. And he can tell from the way Sukuna’s lips curl even further that he can tell how weak Megumi is.
Weak and vulnerable.
Sukuna takes a step closer to the bed. “I think you know what I'm doing here, do you not?”
Unfortunately, Megumi has an idea.
He shuffles back on his bed, closing his knees to try to cover himself. But there's no use. Even if Sukuna can't see him, he can surely smell the slick dripping from Megumi’s pussy, thick and heavy and filling the room, keeping Megumi’s head just a touch too cloudy.
Megumi lifts his arm, shaky hand pointing at the door. “Go away.”
Sukuna takes yet another step further, and as he opens his mouth to speak, he suddenly winces, a grimace coming to his face.
“No, that does not break terms,” he says out loud. “You have to give me more than a minute to convince him.”
Megumi stares, head cocked to the side in confusion.
“The brat is being difficult,” Sukuna explains, and then he lets out a breath. “But he'll be quiet now. Now it's just the two of us.”
Megumi doesn't know how he feels about it being just the two of them. On one hand, the idea of being truly alone with Sukuna is enough to make him tremble with fear. On the other hand, he doesn't particularly want his best friend seeing him like this.
“What are the terms?” he asks after a moment.
Sukuna’s smile returns. “I can't force myself on you. I can't hurt you unless you ask me to. And in return, I become less of a… nuisance for Itadori.”
“And Itadori agreed to this?”
Sukuna takes yet another step closer. Now he's looming over the bed, staring down at Megumi. “He knows this is what you need, little omega. And since he isn't strong enough to come in here and do it himself, he's graciously allowed me to take what's rightfully mine.”
“Rightfully yours?” Megumi exclaims. “What the fuck are you—”
But his question is cut off by a pang in his stomach, and he curls in on himself, letting out an oof.
Sukuna chuckles. “See, your body is responding to me so perfectly, little sorcerer. Like it knows who its alpha is. Like it knows just what it wants.”
Megumi shakes his head, sweat dripping from his forehead as he leans back further, wrapping his arms around his waist. He’s cramping up worse than ever before, his whole lower body practically zinging with discomfort and arousal. It's like his heat suddenly went from a safe spot to its highest setting in hardly a second.
Fuck, maybe Sukuna is right.
“I—I—” Megumi stutters, the bed shifting as Sukuna climbs on in front of him.
“I know just what you need, sweetheart. I will take such good care of you,” he says, his voice shockingly gentle. “I will make it not hurt anymore. Isn't that what you want, Megumi? For it to not hurt anymore?”
Yes, Megumi thinks desperately. He whines, eyes fluttering closed for a moment. He feels sick. He feels sick and desperate and Sukuna’s scent is surrounding him so, so dangerously. He smells so incredible—warm and masculine and alpha—and Megumi has never smelled something like that while in heat before. He hadn’t known just how much it would affect him.
Sukuna takes Megumi's chin, tilting it up so they're forced to meet gazes as Megumi’s eyes shoot open again.
“Let me help you, little omega,” Sukuna says, fingers digging into Megumi’s chin. His voice is somehow both soft and teasing. Gentle and cutting. It makes Megumi shiver. “Let me show you what you were made for.”
Megumi’s mind short-circuits. Yes, he wants to be helped. Yes, he wants to be taken care of. Yes, he wants to be shown what his body was built for but has never before received.
And Sukuna is the only one here to show him.
Megumi nods, a whimper bursting free from his throat as he surges forward, pressing his lips against Sukuna’s. Sukuna responds right away, growling against his mouth and wrapping his arms around Megumi’s waist, tugging him forward so Megumi is seated on his lap. He licks into Megumi’s mouth sinfully, tongue curling around Megumi’s as he pushes his hips up, grinding right against Megumi through the confines of their pants.
More slick pools in Megumi’s boxers as he starts to move his own hips, meeting Sukuna thrust-for-thrust. He can hardly believe it—if you’d told the Megumi of just a few hours before that soon he’d be in heat, dry humping Ryoumen Sukuna he would have laughed in your fucking face. But right now… Right now, it feels so perfect. It feels so satisfying and electrifying and Megumi needs more. He needs more and he needs it now.
He squirms around, moaning helplessly as he ruts against Sukuna, tears starting to drip past his eyes. Sukuna chuckles, disconnecting their lips. One hand squeezes Megumi’s waist while the other reaches up to card through Megumi’s messy hair, tugging ever so gently. Much more gently than Megumi ever would have expected from him.
“Don’t think about anything, sweetheart,” Sukuna whispers. “Just be a good omega and let me take care of you. Let that pretty little head go empty. You don’t need to think. You’re mine now, Megumi. That’s all you need to be.”
Megumi’s inner omega purrs. This is what he didn’t know he wanted. In all of his heats, he’s always felt so unsatisfied, and this is why. This is what he’s needed—to not have to think. To not have to do anything but receive and give pleasure. This is what his body has always been meant for.
And Sukuna—cruel as he is—is going to give it to him.
Megumi’s head goes blissfully blank.
***
Fushiguro Megumi is a beautiful little thing.
Sukuna has always known it. Who would he be if not an appreciator of the greater things in life? He has always been drawn to those who are fascinating. Dangerous. Powerful. And yes, beautiful.
And Megumi is all of those things and somehow more.
Megumi nearly slumps forward, arms around Sukuna’s neck as he continues grinding forward, rutting against Sukuna’s still-clothed cock. Sukuna senses the instant submission, and he can’t help but smile. Megumi may have plenty of bite in regular life, but now, he’s putty in Sukuna’s hands, perfect for Sukuna to mold. He’s nothing but a plaything, chasing his pleasure desperately and trusting Sukuna to give it to him.
Good boy, Sukuna thinks, rocking his own hips harder, hands pushing down on Megumi’s waist. He hears and feels when Megumi suddenly comes, a whine bursting free from his lips as his thrusts stutter, but the scent is the most wonderful part. More slick leaks out of Megumi, and the sweet scent of it makes Sukuna’s head swim. He fucked plenty of omegas in his time, but never one so unbearably delicious smelling.
Yes, Fushiguro Megumi was just made for him.
Megumi is twitching and panting with aftershocks, still gently fucking his hips down when Sukuna decides he’s grown impatient. He shoves him backwards so he lands on his back, crawling between his spread legs and taking hold of the hem of his sweatpants. Sukuna tugs them down, boxers and all, nearly moaning when the scent of Megumi’s slick grows impossibly stronger. He tosses the soaked boxers and pants behind him, pouncing forward to wrap his hands around Megumi’s thighs, shoving them backwards and leaning down to nose at his pussy. Sukuna wants to taste him. Desperately.
He licks at Megumi’s opening, the taste of slick so sweet on his tongue that he groans. Sukuna cleans him up sloppily, fucking his tongue in and out as his hand finds Megumi’s clit. He pinches it, making Megumi yelp, and then he starts to rub it firmly, just a tad rougher than Megumi probably would do to himself. Megumi cries out at the feeling, hands landing in Sukuna’s hair. Whether he’s trying to push him away or pull him closer is unclear, but Sukuna doesn’t care either way. He’s not planning on going anywhere.
Megumi’s cries turn to sobs of pleasure when Sukuna opens up the mouth on his hand, extra tongue coming out to flick over Megumi’s swollen clit while Sukuna continues drinking down the fountain of slick streaming out of him.
“Suk—Suk—Suk—” Megumi tries, and Sukuna’s stomach tightens. He’s suddenly desperate to hear his name leave Megumi’s lips in that whiney, desperate voice.
He pulls his face back, leaving his hand licking and sucking at Megumi’s clit. He can feel how wet his lips and chin are, shiny with slick and spit. Sukuna doesn’t mind the sloppiness. He slips his other hand down to thumb at Megumi’s opening, just barely pushing in and out of the tight—nearly too tight—hole.
“Look at this little cunt,” he says, pushing his thumb in a bit further, making Megumi gasp. “So tight and pretty. And all for me, yes? Just for me?”
Megumi tries to say something, but it gets cut off by another gasp when Sukuna slides his thumb in further, forcing him open.
“Hm? What was that?” Sukuna starts to fuck his thumb in and out. “Who does this pussy belong to, sweetheart?”
He can tell Megumi is fighting it. This is probably taking it too far. But Sukuna is going to push anyway. He’s going to own Megumi, and he wants Megumi to say it.
He pinches Megumi’s clit, and Megumi sobs again, tears spilling down his pretty pink cheeks. He already looks so wrecked, and they’ve only just gotten started. How nice.
Sukuna leans closer, bringing his face just inches from Megumi’s.
“Fucking say it,” he hisses. “Tell me who this cunt belongs to, and I’ll let you come. Don’t you want to come again, baby? Don’t you want me to make you feel good?”
More tears leak down Megumi’s face as he shakes his head, lips opening on a silent scream. The scream becomes audible when Sukuna pulls his thumb free, instead shoving two of his fingers straight into Megumi’s pussy while still pinching his clit with the other.
“Say it, Megumi,” Sukuna commands again, and he watches in satisfaction as Megumi cracks.
“You,” Megumi cries. “It belongs to you! It’s your pussy! Yours!”
Sukuna nearly growls. “Say my fucking name. Who’s your alpha? Who owns you?”
“Sukuna,” Megumi sobs out as he comes a second time. “Sukuna, Sukuna, Sukuna.”
Ugh, it’s so perfect.
Megumi is so perfect.
Sukuna can’t take it anymore. He needs to bury himself in this perfect omega. Fuck him open and gaping and then knot him so perfectly. Breed him, fill him up with Sukuna’s seed. Get him pregnant, heavy and swollen with their pups so Megumi can never even think of going somewhere else.
No sooner has Megumi finished coming than Sukuna is ripping his fingers free, tugging off his pants and shirt before shooting forward, bending Megumi’s thighs back into his chest once more. He pushes forward, burying himself fully inside Megumi on just one thrust. Sukuna’s cock is large enough that Megumi cries at the stretch, eyes scrunching closed. But Sukuna will have none of that.
He grabs Megumi’s cheeks, squeezing tight. “Open your fucking eyes. Look at me while I fuck you,”
Megumi obeys, eyes wet and wide as he stares up at Sukuna. There’s a glassy, vacant look in them that tells Sukuna he's been successful. He’s fucked every thought out of the omega’s pretty little head. In this moment, Megumi is nothing but a perfect fucktoy for Sukuna to do what he pleases with. To take his pleasure in.
There’s something immensely satisfying about that. Fushiguro Megumi—difficult and powerful and endlessly complex—has been reduced to nothing but a thing for Sukuna to fuck into. To use.
But strangely, Sukuna doesn’t want to use him. No, he wants to give back. He wants Megumi to feel just as good as Sukuna does. Because after all, doesn’t Megumi belong to Sukuna now? And doesn’t Sukuna take care of his belongings?
He fucks Megumi hard and rough—bordering on too rough—for several minutes before finally reaching down to find Megumi’s clit yet again. Megumi sobs at the contact, eyes fighting to close again, but he dutifully keeps them open, hazy and locked on Sukuna.
Perfect. Perfect. He’s so perfect.
And in that moment, this perfection belongs to Sukuna.
Sukuna swings Megumi’s ankles over his shoulders, shoving his legs back in a perfect mating press. He can feel his knot starting to swell and catch on Megumi’s opening. Megumi must feel it too by the way he whines, hands squeezing Sukuna’s shoulders tight enough to leave bruises.
“Alpha,” he gasps out, and Sukuna groans, knot swelling even fatter. He likes the sound of that word coming from Megumi’s lips. He wants him to keep on saying it.
“You’re mine,” he hisses, his mouth getting away from him. “My omega. No one else will ever have you. I will fucking kill anyone who tries to put their hands on you. Understand?”
It’s an empty promise, and Sukuna knows it. As soon as Megumi’s heat ends and Sukuna’s deal with Itadori is over, the brat will take back over and Sukuna will be annoyingly stifled yet again. But it’s the thought that counts. The thought that drives Sukuna crazy.
Megumi gasps, crying again, but that’s not good enough.
“Understand?” Sukuna repeats, punctuating the question with a punishing thrust.
“Yes,” Megumi cries. “I—I understand. I—I—”
He comes for a third time, tears streaming down his face as he writhes and twitches, hips lifting off the bed as best they can with Sukuna holding him in this position. He tightens around Sukuna’s cock, and that's it. Sukuna’s knot pops to its full size and he thrusts it deep inside, cum spurting from his cock and flooding Megumi’s insides. Megumi sighs at the feeling, and Sukuna knows that his inner omega must be pleased. How could it not be, when an alpha like Sukuna has just knotted and bred him so perfectly?
Sukuna feels his canines elongating, his vision tunneling as his orgasm seems to go on and on and on. Still folding Megumi in half, he leans forward and noses at the scent gland on his throat, teeth aching.
Sukuna smiles against his skin. Luckily that stupid brat hadn’t thought to forbid this in his terms.
He opens his mouth over Megumi’s scent gland and bites down hard, pleasure erupting in his chest when he feels his teeth pierce the skin of Megumi’s throat. Megumi squirms and cries and shockingly seems to come yet again, spasming around Sukuna’s knot over and over again. Sukuna continues pushing his hips forward as long as he can, fucking his cum impossibly deeper inside as he laps up some of the blood leaking from the bite mark on Megumi’s throat.
The bite mark that ties Megumi to Sukuna forever. That proves beyond the shadow of a doubt that Megumi belongs to Sukuna. His omega. His to fuck and breed and worship and ruin.
Surely Megumi will be angry when his senses return to himself. He will likely shout at Sukuna and throw a little fit. That’s alright. Sukuna can handle him. And besides, there’s no point in throwing a fit. What’s done is done. Megumi has been claimed, and now no one else will ever touch him.
Sukuna smiles yet again. Yes, Fusiguro Megumi is a beautiful little thing.
And now he’s Sukuna’s.
Forever.