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Naturally, Moondae is the first to notice it.
Ahyeon is not the type to keep his distance, but he goes the extra mile to avoid getting in the way, so when he starts clinging to Moondae at every opportunity, alarm bells start ringing in the back of his head. He tries to warn the staff; however, it's the tail end of promotions for their new mini album, and since he's an omega, they take his words as him being overly worried about a team member and nothing more.
And worried Moondae is, but not for the reason they think.
Despite Bae Sejin being right there, the omega Ahyeon set his sights on is none other than Moondae himself, and for the rest of the promo period, he isn't able to go anywhere without Ahyeon at his heels. It's gotten even worse than it was back when they were on Idol Inc., since now Ahyeon is unconsciously showering him in pheromones.
Moondae has the implant, but even with his strict heat management, it's hard on him if an alpha like Ahyeon is naively running around practically screaming he wants to mount him.
The busy schedule had given him some respite, though. Ahyeon kept peeking at him at any chance he got, which were few since Moondae was paired more often with Eugene and Raebin than with Ahyeon, but as the promotions ended and they got a few days off, Moondae was sorely reminded of why he should never let things like that be left alone to fix themselves.
For example, now, when he should be sleeping on his bed, wasting away after arduous days of hard work, he's stuck in Ahyeon's embrace even though he's pretty sure he'd fallen asleep alone after seeing the other members out. He knew Ahyeon was still in the dorm, probably waiting for his parents to pick him up, but Moondae wrongly assumed he wouldn't need to worry about Ahyeon anymore and went to bed.
The weight against his back and the sweltering temperature in the room speak for themselves. Ahyeon's rut arrived, and he's come looking for the omega he had been scenting to alleviate the discomfort.
Thankfully, Ahyeon is asleep, his long eyelashes fluttering softly. Moondae manages to disentangle himself from his grasp, and instead of moving away and calling their manager like he's supposed to, he stands there at the bed's feet, watching him.
Ahyeon's fringe is sticking to his forehead, and his eyebrows are scrunched up in pain. Moondae was definitely releasing pheromones to calm him down because now that he's moved away, Ahyeon's breathing is starting to get deregulated.
Both Chungwoo and Keun Sejin went through their first rut before debut, so now it's just a matter of managing it through careful treatment and medication, but Ahyeon is an atypical late-bloomer. He's still in the phase of testing medication to see what works best for his body, and since he's also an idol, they've been giving him doses of blockers way above the recommended dose to avoid any accidents with fans or outside staff who might be omegas.
All these factors lead to a complicated conclusion: even if he calls the manager, there's no way to control Ahyeon's rut with reducers at this point. They'll have to sedate him.
It's not a big deal. It happens all the time in modern society—one or two days at most. Ahyeon will be well taken care of.
Moondae walks around the bed and runs the tip of his fingers over Ahyeon's scent gland. Ahyeon squirms, his eyes trembling open.
"M-moondae," Ahyeon's low register sounds unusually rough. "What am I doing here?"
Moondae crouches down so they're eye level. "You're in rut."
Ahyeon blinks. "Um, w-what?"
"You didn't notice?"
Ahyeon shakes his head. "N-no. I just thought I was c-coming down with a cold."
Moondae sighs, then climbs back on the bed. Ahyeon watches him with unfocused eyes.
"Do you want my help?"
"Help?"
"It's going to get more and more uncomfortable," he points to Ahyeon's crotch with his chin. "It's going to hurt. If I get you off first, there's a chance the reducers might work."
Ahyeon doesn't really look like he's processing Moondae's words, but he nods anyway. Moondae tries getting a more verbal response, but before he can even try, Ahyeon's face distorts into pain.
With nothing else to do, he reaches for Ahyeon's pants, hoping he won't regret this.
…
Moondae watches Ahyeon closely. The handjob didn't do a lot for him. His pupils are dilated, the inside of his hand is littered with scratch marks from him sinking his nails into his palms. He looks pitiful, lying under Moondae with his cheeks red and unshed tears at the corners of his eyes. At least he's not as dazed as before anymore.
Before he can realise what he's doing, Moondae is running his fingers through Ahyeon's hair, wet with sweat, and kissing him. Ahyeon makes a small startled noise, but opens his mouth obediently, clumsily trying to keep up with Moondae.
First of all, it should be made clear that Moondae doesn't have a virginity kink. As Ryu Gunwoo, all the omegas he slept with were either more or as experienced as him.
But Ahyeon is quite something on his own. Even with his hard-on persistently pressing against Moondae's ass, he doesn't try to seize control. He squirms and whines and lets Moondae do whatever he wants, like he's never even masturbated before.
"Do you have condoms?" Moondae asks when they separate, his voice strained.
Ahyeon blinks dazedly at him. Moondae bites his lips to wake him up and repeats the question.
"I-I don't think s-so," he says. "I d-didn't know that, um."
He trails off, disappointment clear in his eyes. At this pace, he might actually cry. Poor guy.
Moondae hums, suddenly grinding against Ahyeon's crotch. Ahyeon moans loudly, his hands flying to Moondae's hips. It's not a forceful grip, more like he's trying to find something to anchor him before the current of lust drowns him.
"It's alright," he shushes Ahyeon, moving in a slow rhythm. "I had my check-up last week. The doctor said the contraceptive implant is working just fine."
"N-no, we c-can't!"
"Aww," Moondae plants a small kiss against Ahyeon's Adam's apple, feeling it move when he swallows. "Are you scared of getting me pregnant, Ahyeon-ah?"
A flicker of consciousness tells Moondae he shouldn't be egging on an alpha at the cusp of a rut, but perhaps the festival of pheromones filling the room is messing with his head as well because he can't entertain any thoughts that don't include Ahyeon under him.
He bends down, slipping his face into the crook between Ahyeon's neck and shoulder.
"Oh, I guess 'scared' wasn't the right word," he trails kisses all the way to Ahyeon's ears, delighted. "Our Ahyeon was just pretending to be a good boy, after all."
"I was not!" Ahyeon tries fighting back, but he does it just as Moondae's hand reach his underwear, and the words come out strangled and desperate.
"Right, right," Moondae laughs. "And as the good boy you are, you're going to fuck me, aren't you, Ahyeon-ah?"
Ahyeon makes another weird noise and then starts rambling about something that Moondae is not interested in. He nuzzles against Ahyeon's neck, rutting against his stomach. He's getting wet, slick running down his thighs.
He was surprisingly pleased when he first saw Ahyeon's cock, despite not having lots of time to admire it in the previous situation. It's big but not too big or exaggeratedly thick; it's gonna slide in nicely.
He pulls Ahyeon up, shuffling both of them backwards until Ahyeon has his back supported against the headboard. Despite the previous complaints, Ahyeon lets himself be commanded without much fuss, even if he keeps giving Moondae these adorable affronted glares.
Ah, who would've thought alphas could be so cute?
"I'll take the pill tomorrow, ok?"
It's better to ease Ahyeon's mind of any weird thoughts brewing inside his head now. Considering he's already in an extremely vulnerable moment, letting him get all anxious on his own won't do any of them good.
Ahyeon, to his surprise, shakes his head. "I-i can go buy i-it."
Moondae stares at him. "The closest pharmacy is twenty minutes away by car."
"There's a CU close by!"
"And you're going to a convenience store, covered in an aroused omega's pheromones, to buy condoms? Really?"
"A-are you marking me?"
Moondae rolls his eyes. Of course that out of all things he said his alpha would choose this detail to fixate on.
"Of course I am," he says, rispid. "Bae Sejin is not here, but I can smell him all over the house, and you're about to mate with me. It's instinctual. You didn't have biology classes when you were at school?"
It's Ahyeon's own fault, really. For being clueless, for basically staking claim on Moondae while clumsily behaving like he's everyday's sheep, for being cute and handsome and for crying so prettily to the point Moondae wants to lick his—Ok, maybe he is losing his mind.
"Anyway," he sighs. "Are we doing this or not? If you're not feeling up to it, we can try working something out for you, and I'll look—"
"No!" Ahyeon cuts him off abruptly. "I'm not letting you do t-this with someone else."
There's a flash of anger in Ahyeon's clear eyes. Moondae flinches in surprise, wondering what might've been said that elicited such a reaction, and recalling his words, he understands what might've struck a chord.
"I wouldn't go looking for someone else, Ahyeon," he says, soothingly. "I would just take some reducers and ride a dildo or something."
Ahyeon gets impossibly redder than he already was and goes on a stuttering rant, even sneaking a few complaints about Moondae's wording.
"You didn't let me finish," he smirks, using his free hand to grab Ahyeon's crotch while he's distracted. "I'm taking it as permission, then. Considering it's your first time, it's best not to use a condom. But don't ever skip it with anybody else, yeah?"
Ahyeon nods, then, thinking better of it, asks in a whisper. "Only with you?"
Moondae laughs, turning around so his back is pressed against Ahyeon's chest. He takes Ahyeon's hand in his and shoves it into his own briefs. They fumble around until Moondae correctly guides Ahyeon's index finger against his wet entrance.
"Only with me," he says, and pushes the finger inside.
…
It's hard teaching someone else how to prep you, Moondae finds out.
During his first time, he and the omega he was dating at the time were both equally inexperienced, but since Gunwoo wasn't the one being spread open, the whole thing went down a lot easier in his memories. Ahyeon's fingers, despite being thin, are ridiculously long. Sometimes he pushes against just the right spot, and at others, he gets overly excited and moves at awkward angles.
It's not enough to make either of them go limp. Ahyeon is an enthusiastic fast-learner, and when he gets it right, Moondae feels every nerve in his body come alight with pleasure.
"Ahyeon-ah," he mumbles when he starts getting so wet, the loud noises of Ahyeon working him open make him feel self-conscious. "That's enough. You can put it in."
Ahyeon doesn't say anything; instead, he nuzzles against Moondae's scent glands and shoves two of his fingers even deeper. Moondae gasps, trying to stop him by getting a hold of his wrist, but the pleasure makes him weak, and soon he's too busy coming all over the sheets to move a single limb in protest.
Either because of the heat or because he's come once already, Moondae doesn't have enough strength to stay on all fours, so he lies down on his back and spreads his legs to invite Ahyeon in.
"D-do I-i—"
"Calm down," Moondae pats his shoulder, hugging Ahyeon's waist with his legs. "I'll help you get it in."
Ahyeon nods, then flinches a little when Moondae uses his own slick to lube up his dick. He plants both hands on each side of Moondae's head as Moondae slowly gets him in. The breach is painful, but not as painful as he thought it'd be.
He knew omegas' bodies were more resistant to pain, but he didn't think it'd be to this extent, the pain laced with sparks of pleasure. He moans Ahyeon's name out of reflex, and Ahyeon, for whatever reason, seems to take it as a complaint.
"S-sorry! D-do you want me to pull it out?"
Moondae shakes his head, but Ahyeon already started moving, his cock dragging out, feeling both strangely uncomfortable and exhilarating.
Instead of pulling out completely, Ahyeon slams back in as Moondae pulls him back. Moondae sinks his nails into Ahyeon's arm, clamping his lips together to avoid screaming. It's a weird feeling, something big and heavy lodging inside him. The noises it makes at every thrust, a lewd squelch that if Moondae were even a little more himself, would have him coiling in embarrassment, but in this state, it only feels right. Like he's exactly where he should be.
He can see that Ahyeon is still keeping himself on a tight leash, though. And well, what's the fun in that?
"You have to go deeper, alpha," he mumbles. "Up here."
He taps where he vaguely thinks his womb is, and it seems to work. Ahyeon thrusts into him with renewed vigour. He rams into Moondae's prostate with ease, and Moondae dazedly wonder if that's an alpha instinct or just Ahyeon's natural disposition to be good at everything.
It gets harder and harder to maintain any coherent train of thought as Ahyeon picks up the pace, holding Moondae's waist at an angle that makes it easy for him to hit all the nice spots. Moondae is forced to stay in an odd position, the pleasure melting his mind into a mush. He moans increasingly louder, gripping the sheets to alleviate the pressure.
At some point, Ahyeon drives so deep inside him that Moondae actually thinks he might poke through his stomach. The thought is deliriously alluring, making him come again.
When he comes down from his high in a few seconds, Ahyeon's ceased all movement and is looking at him—with tears dripping down his face.
"What happened?" Moondae sits up in alarm. Except he forgets he's still very much impaled on Ahyeon's dick, and the abrupt turn makes him shiver. Ahyeon still is his priority, though, so with trembling arms, he pulls his alpha into a half-hug. "Did you get hurt?"
"No," Ahyeon mumbles, sounding absolutely crushed. "I c-called for y-you but you d-didn't answer. B-because I hurt you."
Ah, right. Ahyeon is a young alpha fucking the lights out of an omega in a semi-heat for the first time. Moondae forgot about that for a second while he was getting his guts rearranged.
"I'm fine, Ahyeon," he says. "I'm—well, I egged you on, right? You did nothing wrong. The opposite, really."
Ahyeon doesn't seem too convinced. Moondae almost tells him that this is not his first rodeo, so Ahyeon doesn't need to worry about him so much, but that'd be hard to explain because Park Moondae is, in fact, a twenty-one-year-old virgin. Not to mention that since his gender was different in his previous body, he could technically be considered one in this body too.
If logic is not working, seduction will have to do the job. Moondae is getting tired.
He tentatively shifts, and Ahyeon reacts immediately, holding him down.
"Is it good?"
Ahyeon nods, his eyes closed tight. He's so cute. Moondae bites the tip of his nose, and trails kisses down to his jaw. Moondae picks up the pace, bouncing up and down with the little strength he has left in his thighs.
He's about to make a joke about their position when Ahyeon bends his body until his chin is nearly touching the mattress and hammers into him without the previous restraint he had been showing all this time. There's no time for a warning, but just the pressure expanding inside Moondae tells him all he needs to know—Ahyeon's rut is breaking, and he's about to knot.
Moondae isn't exactly ready for a knot. Alphas rarely knot on their first rut, mostly because their bodies are still maturing, and he thought Ahyeon, being a late-bloomer and all that, would take at least a few more years. But nope. Maybe it's because both his parents are alphas?
Ahyeon thrusts his half-formed knot inside him, forcing a third orgasm out of him, and not long after, comes in him. Moondae, feeling dizzy from what he's pretty sure was a dry orgasm, barely registers as Ahyeon lies down and pulls him on top.
"H-how's your body?"
He huffs out a disgruntled noise, acutely aware of the cum sloshing around inside him.
"I feel like a cream puff," he says. Ahyeon chuckles, even though he tries hiding it; the vibrations of his laughter reverberate against Moondae's chest. "It was fun, though."
"It was," Ahyeon says after a brief moment, his voice heavy with sleepiness.
Moondae lets him doze off, they'll be up in a few hours for a second round when Ahyeon's rut flares up again, so they should get as much rest as possible.