Chapter Text
Katsuki could tell as soon as he woke up that something was off. That "something" being that his heat has started. Fucking great, just what he needs, to be all emotional and unfocused all day.
At least his heats aren't that bad, Katsuki thinks to himself while pulling on his clothes for the day. Being some horny, needy omega is beneath him anyway. He doesn't even nest! Well, most of the time, anyway.
His instincts aren't very strong at home, since his father is an omega and his mother is a beta. There have been a few times where spending time around his heat with Izuku have triggered some stronger responses, but even then, they're not too bad.
He thinks it shouldn't be any different now that he lives in the dorms, even if his class is literally half alphas. He just... doesn't react. The need for an alpha is beneath him anyway.
He keeps this mentality as he makes his way downstairs to the commons, his mind already wandering to what to make for breakfast as he's fully convinced this will just be another normal day.
He stops dead in his tracks when he gets to the living room, the scents of the others gathered there hitting him way harder than they had any right to. Specifically the alpha scents.
He scans the room to look for the source of the offending scents. The first one he can confidently place is Kaminari's, like static after a thunderstorm. The second is easier, Sero, giving off something savory with an earthy undertone. A few others are around, but they don't stand out to Katsuki as much.
He shrugs it off, making his way to the kitchen without stopping to talk to any of them, not willing to run the risk of possibly being more affected somehow.
He pauses in the doorway to the kitchen, two dominating scents flooding his senses. His eyes first land on Iida, cooking eggs on the stove. The scent of diesel and smoke fill his nose as he focuses on the blue haired boy's scent, but that's not the one that stood out to him.
Katsuki's eyes lock onto Kirishima, who's leaning against the counter, protein shake in hand (gross.), and talking to Ojiro about... something. Katsuki will admit that he is not paying attention to him. What he is focused on, however, is the scent of rock dust and something distinctly masculine that Kirishima gives.
Katsuki loses all pretense of thinking he would not be affected by his heat. He can feel his limbs start to shake, his body temperature rise, and he swears he can feel how wet he gets.
Then, Kirishima's nose twitches, and he stops mid-sentence to Ojiro, and Katsuki has to physically surpress a whine when Kirishima turns his eyes to him.
Katsuki then decides that socializing right now is not in his best interest, actually, and promptly turns on his heel and very calmly walks (see: damn near sprints) back to his room.
Once he gets inside his room and locks the door, his gaze immediately falls on his neatly made bed, and he scowls at it in distaste.
... No fucking way. This is not happening. He does not want to fucking nest right now. ...Except he fucking does. He stares at the bed for a long moment, fighting every instinct and trying to shove them down. He breaks after less than a minute.
Katsuki sulks over to his bed, and yanks all the blankets off and drops them onto a heap on the floor. He carefully rearranges his pillows into an approximately circle-esque shape on the bed, then starts arranging his blankets over them, fluffing them up and pawing at them for the next few minutes to get them exactly how he wants them.
After he's deemed the nest acceptable, Katsuki curls up in the soft fabric, and immediately notes that it's missing something. He really tries not to think about how the first thing he thinks of is Kirishima's scent. Maybe he'll settle for stealing one of Deku's hoodies later. Gods know the nerd's always desperate to help Katsuki out during his heats.
Katsuki's pulled out of his thoughts by a knock on his door, and he seriously considers ignoring it, but then, another knock, this time accompanied by a familiar voice.
"Hey, Bakugo, it's me, man, you okay?"
Kirishima. Now that Katsuki's paying attention, he can just barely catch that scent that's driving him crazy. He's up and opening the door before he even realizes that he moved.
As soon as the door's open, the delicious scent sends a wave of heat through Katsuki's body, and he has to grip the doorframe to keep his legs from buckling under him. Kirishima looks concerned at first, his eyes scanning Katsuki, then the room, then going soft with understanding when he sees the nest in Katsuki's bed.
"Just wanted to see if you were alright, man. You ran off pretty quick earlier, so..." Kirishima answers before Katsuki can even ask. "Yeah, I'm fucking fine, shitty hair." Katsuki responds, closing his door down a bit, feeling oddly protective of his nest despite Kirishima being the one he wants in it.
"Cool. Well, if you need anything, water, something scented, or just some company, I'm available." And that's new. Deku's the only person who's never babied Katsuki during his heats, and that's only because the nerd knows it'd just piss Katsuki off. It makes him crave Kirishima that much more.
But, contrary to popular belief, Katsuki has a very strong willpower and even stronger self control, so he does not pounce the alpha, and does not drag him into his nest.
"Oh. Thanks, or whatever." Katsuki mutters in response, and Kirishima gives a bright smile before turning to leave. Immediately, Katsuki's omega panics, already longing for his the alpha back.
"Hey, hold up," Katsuki calls after him, something inside him settling once he has the redheads attention back on him. "I guess, if you really wanna help, having something of yours scented wouldn't... hurt anything..." He finishes, turning his face away to try and hide the blush forming.
Unfortunately, that means he can't see the knowing grin Kirishima has that Katsuki can hear in his response. "Yeah? Alright then, lemme just grab something."
Katsuki watches in his peripheral as Kirishima ducks into his own room for a second, then comes back with a hoodie. It looks like it'd fit Kirishima perfectly, but Katsuki knows it'll be too big on himself.
Katsuki practically rips it from Kirishima's hands as soon as he's close enough, and earns a chuckle and hair ruffle for his efforts.
"Anything else you need right now?" Kirishima asks, and Katsuki shakes his head, bringing the hoodie up to his nose to inhale that scent he was craving so badly. Kirishima smiles at him again and gives him one last hair ruffle, and then he's walking away.
Katsuki watches him go, then locks himself back in his room, crawling into his nest with the new addition. He curls around it, burying his nose in the soft fabric to get more of that mind-numbing, pleasent dizziness that comes from breathing in Kirishima's scent.
Fuck, with the scent he'd been missing filling his senses, Katsuki can feel himself grow wetter, a persistent throbbing making itself known between his thighs.
Katsuki tries to ignore it, squirming and nuzzling into his nest, the still logical part of his mind telling him that he absolutely should not get off to his best friends scent.
Unfortunately, the horny, desperate omega part of his mind does not care about social normalities. Katsuki bites a blanket to muffle a whine, inhaling the scent clinging to the hoodie one last time before effectively losing all sense of pride as he shoves the fabric between his legs.
Even as he starts rolling his hips against it, his thoughts are everywhere. 'Not fucking fair. I never get this fucked up from this. It's all that stupid rock head's fault.' He muffles another whine at the thought of Kirishima, big hands, big heart, and those fucking shark teeth Katsuki pretends to hate. 'Fuckin' hell, I wonder what it'd feel like if he bit me...'
Katsuki realizes with no small amount of frustration that his jeans are getting in the way of how much stimulation he's getting, and he takes a moment to angrily yank the offending fabric off and toss them off the bed somewhere.
He shoves the hoodie back between his legs, rolling half onto his stomach with one leg hiked up to hump against it. Gods, how the fuck did he let himself get this fucking desperate? He's acting like some pathetic breeding bitch, and if he's being honest, he's never been this fucking wet.
He brings a hand up to cover his mouth, pathetic whimpers and whines falling from his lips as he tries to get himself off. After a few infuriating minutes, he realizes it's not fucking enough.
With no small amount of frustration, he shoves the hand that's not over his mouth into his boxers, stretching his arm to sink two fingers deep in his cunt, a high pitched moan leaving him before he can stop it.
He fucks into himself hard and fast, the ridiculous amount of slick dripping from him making the slide smooth. He tries his best to keep quiet, to surpress the moans and whimpers, but he knows he's being loud.
He also knows that in this moment, he doesn't care. He can feel that tension building in his gut, can feel himself twitching and throbbing, and then, he feels that tension break.
He cums with a broken moan that even he can admit sounds vaguely like Kirishima's name, making a mess of his boxers, and probably the hoodie still stuffed between his legs.
Katsuki takes a few moments to recover, just catching his breath, before tenderly removing his now soaked hand from his boxers, pulling the hoodie up to his chest, curling up, and promptly passing the fuck out.