Chapter Text
Any hero knows that a sex quirk is no joke. Anyone who waggles their eyebrows like it’s all fun and games is either all talk or terribly naive.
Shouto might be naive in some matters but he is not a fool. He knows that, at best, it’s a lengthy ordeal— even with a trusted partner who’s willing to help with that— and at worst? Blistering agony, until it’s either dealt with properly or until a medic drugs the poor, unfortunate soul into a coma.
The medical establishment is, understandably, reluctant to make the latter an option in most cases. Don’t ask how Shouto knows about that. He’s always been a cautious hero, does his due diligence, plans for future contingencies.
A sex quirk is no laughing matter, and this is a particularly nasty one, apparently.
Every hero and sidekick on the scene got hit with the quirk— except for Shouto, who seems remarkably unscathed in the aftermath. Those affected are told they need to have a great deal of vigorous sex to get the quirk flushed out of their systems.
No one will die if they don’t. They can refuse treatment if they choose, but there’s a specialist on the scene now and she has seen this quirk in action before. She calls this one a ‘lust quirk,’ saying that it intensifies sexual attraction and compels the victim to satisfy those cravings. Although Shouto heard the whole briefing, he still doesn’t think he could say why that is any different from the last sex quirk that hit another unit of heroes just last month.
Shouto probably isn’t the right person to ask; sexual attraction really isn’t his area of expertise.
From what he gathers, the effect will be excruciating if left untreated. Most of the gathered heroes are already sweating over it, arms crossed and eyes averted so that they don’t accidentally look at one of their coworkers while in such a compromised state. The specialist hands out flyers listing various clinics and ‘services’ that can help with this kind of thing before they’re all dismissed. These are relief services, clinical but still sexual in nature; the coma option isn’t on the table, not unless one were to self-inflict— and Shouto forces himself not to finish that thought.
Shouto is near the back of the small crowd, seated on the bumper of an ambulance receiving minor wound care. He is making an effort to listen to the information being presented, because not listening would be quite rude, all while a young paramedic swabs at what amounts to a few minor cuts and scrapes.
Although Shouto believes in taking the proper measures even with minor injuries, he is feeling rather impatient with all of it. Soon he’ll be cleared to go home; he could just as easily get out his own med kit there. Even better, either Katsuki or Izuku would probably sit him down at the table with a frown and do it for him. It’s what they do. They look after each other.
That’s a pleasant thought, so he lets it linger. It helps to push the other thoughts away.
A few steri-strips and light bandages later, the paramedic offers Shouto a couple of painkillers in a tiny paper cup. He blinks down at the capsules like he doesn’t even recognize what they’re offering him.
“I’m fine. Really.”
“I suppose so,” the young medic smiles pleasantly. “You’re lucky, you know. You’d need a lot more than an aspirin if that quirk had gotten you, too.”
Right.
Shouto is still made to take a flyer, ‘just in case’ he starts feeling any of the lust quirk’s effects after he gets home.
Shutting the apartment door, Shouto glances at the paper he was given. The thought makes his skin crawl.
He... doesn’t want to have sex. He’s never wanted it— well, maybe not never, but in the ballpark of never and that’s good enough for Shouto to decide the matter is settled. Besides, what’s the use in wanting what he knows he can’t have?
There was one time he thought he could want something like that, but then... Izuku and Katsuki fell in love with each other. It was a long time ago, before they were even out of high school. Shouto is happy for them. They deserve each other, and Shouto still has two best friends.
Now the three are roommates and it’s certainly the happiest Shouto has ever been, especially their growing closeness over the last several months. He gets to have two extraordinary people in his life every single day.
There’s Izuku, who loves to sit close on the couch and watch old movies and chatter about all of his favorite parts. Shouto could listen to him for hours and often does. And then Katsuki, who yells at Shouto to take better care of himself and, “Eat a damn vegetable!” which he, considerately, always provides in an extra-large helping when he shoves a bento into Shouto’s hands.
Izuku and Katsuki flirt with each other all the time— not that Katsuki would ever admit that what he’s doing is undoubtedly called ‘flirting.’ They go on some dates, too, and have ‘just them time,’ which Shouto understands to be code for sex.
Sometimes Izuku seems shy about it, but Shouto thinks it’s good that they have that. He’s happy for them. The rest of the time, Shouto can’t get enough of being in their orbit. He gets to feel like he’s a part of what they have.
Shouto wants this life exactly as it is. He has no intention of rocking the boat. The only reason he’s even thinking about it is this dull, persistent ache that he now feels all down his spine, moving into his groin. The feeling has been building for the last hour, but Shouto refuses to think too specifically about what it means.
He doesn’t want to think about ‘fixing’ it— going to a clinic, signing some form, only to grit his teeth as some stranger lays hands on him. Or going to one of their other friends for help, shamefaced and flinching, itching to run away the whole time. He’s not willing to put anyone through that, even if Shouto thought he could bear it himself— and he isn’t sure he could.
Just, no. The mortification and resulting awkwardness in his friendships would surely be considerably worse than the pain, which is tolerable. Pain, Shouto can deal with, has always dealt with in the old-fashioned way that he learned from his father: with a stiff upper lip. With self-control, detachment, and silence. That much is familiar, even if nothing else about this situation is.
So he’ll deal with it. And when it’s over, his life will be right where he left it: full, and good, and unchanged.
“Shouto-kun?”
The sound of Izuku’s voice so close at his back makes Shouto jump. That isn’t the reason Shouto sends the flyer up in flames; he lets it burn to ash consciously, choosing to eliminate any risk that Izuku might catch a glimpse of what the piece of paper says. If he saw that, he would only worry— or worse, try to fix it.
But Shouto is fine. He wasn’t going to use any of those resources, anyway, knowing there’d be no relief in subjecting himself to that. It feels sort of good to watch it burn away. He won’t let some quirk make him do something he doesn’t want to do.
“Oh!” Izuku startles back from the sudden flame, turning red in the face. “I’m really sorry for startling you! Did you need that paper?”
“No.” Shouto looks at the fine ash falling from his hand. “I’ll clean this up.”
“It’s just that you were standing in the doorway a long time.” Izuku stands there in his nightclothes, looking relaxed and terribly handsome. It’s a private side of Izuku that so few get to see. Shouto counts himself lucky every day.
Izuku steps closer, studying him more closely. “Rough night?”
“I guess.” Shouto huffs, glancing down at the minor scrapes the paramedic insisted on cleaning up and wrapping. “This is nothing serious.”
Izuku nods. He’s been given the same overbearing treatment plenty of times, as if Hero Deku didn’t make a name for himself back at UA as the guy who’s more than willing to break all of his limbs for sport.
He still looks Shouto over, appraising whatever small clues he may have left between the lines. “But are you feeling okay, Shouto? You seem distracted.”
“Just a bit tired.” Shouto brushes his hair back out of his eyes and sighs. Why is he sweating? He reaches for his ice quirk and it may be enough to take the edge off of it, but at the same time the cold seems to exacerbate the pain. Sweating it is, then, Shouto thinks morosely. “I think I’ll go take a shower before bed.”
“Sure,” Izuku answers easily. “Kacchan turned in earlier and I’m about to do the same. I have an early patrol.” Izuku grimaces and Shouto thinks that’s incredibly cute; Izuku never has been a morning person, but Katsuki is a good influence and helps to make sure he doesn’t oversleep.
“There’s dinner wrapped up for you in the fridge, okay?” Izuku continues. “It was so amazing, Kacchan’s new recipe. You are going to love it.”
It isn’t that Shouto is surprised by this. It might be more surprising if there weren’t a meal prep container tucked away with his name on it, since they’ve made such a habit of it. Even Izuku gushing about how amazing it is doubles as a tactic to try and keep Shouto from skipping meals.
Shouto knows all this. Still, the easy reminder of the domestic things they share makes Shouto feel suddenly warm and a little fuzzy in the head. It soothes some of the ache, for the span of a breath, at least.
“I’ll be sure to thank him in the morning.”
“He’ll like that.” Izuku steps closer, reaching out to place a hand on his arm. “Then get some rest, okay, Shouto-kun?”
Shouto means to answer him, but his throat suddenly feels too tight. The weight of Izuku’s palm, gently rubbing a path upward to knead into his shoulder, draws his focus like a lure. It absorbs him completely.
It’s all Shouto can do for a moment to stand still and breathe. Izuku is affectionate, always has been, and in his secret heart Shouto enjoys that an awful lot. But right now, that warm feeling shoots inexplicably south, raising the hair all over his body. He wants Izuku’s hands all over his body, possibly more than he’s ever wanted anything.
Oh, no. No.
Shouto swallows. He manages a feeble nod and prays it will be answer enough; he can’t speak or his voice will betray him.
Izuku returns his nod and pulls away. Shouto tries to process that, too, but now his nerves are screaming, crying out for the return of that contact. Shouto very nearly lurches forward after him, to chase his hands, his heat. Izuku heads back into the living room, unaware, and it takes all of Shouto’s willpower to plant his feet and not do something reckless that he won’t ever be able to take back.
Shouto knows now that he underestimated the quirk’s effect.
He expected the pain and the troublesome side effects of not treating his affliction, since he never had any intention of doing otherwise. He still doesn’t. But the truth of it is worse than Shouto understood, because Izuku sets him on fire. For a brilliant moment, Izuku’s presence and his simple, friendly touch took his pain away— replacing it with a blaze, an all-consuming need that Shouto finds altogether more terrifying.
Then Izuku withdrew his hand, and Shouto’s whole body pangs in protest, in disappointment, desperation. He needs it back! That brief touch consumed his thoughts completely and, when gone, Shouto is left burning. In the white-hot aftermath, he’s worse off than he was before because the touch wasn’t enough, wasn’t what Shouto needed.
Of course not. Because he isn’t— they aren’t— no!
Shouto steadies himself on the wall. He keeps his eyes down. He makes himself busy with removing his boots, shaky and uncoordinated as he feels. He tucks away his used gear for later cleaning. He pushes the need away, pushes it down, so that when Izuku finishes tidying the sofa and turns back around there is hopefully no sign left of Shouto’s internal struggle.
A shower, yes, that’s what he was going to do next. A shower should help clear his head, and wash away these urges before they take hold.
Izuku is a friend. His best friend, who is very happily in love with his other best friend. Izuku doesn’t owe Shouto anything, and certainly not the things he’s suddenly imagining him doing with his beautiful, rough hands.
“You sure you’re alright?” Izuku hovers outside the hallway that leads to their bedrooms— Izuku and Katsuki’s room on the left, and Shouto’s smaller bedroom on the right.
Izuku’s brow is furrowed, his expression dangerously close to worry. Shouto can’t let him worry. He exhales as calmly as he can.
“I just really need to turn in,” Shouto assures. He even relaxes by a fraction once Izuku seems to accept that answer. See? He can do this. “Goodnight, Izuku. Sleep well.”
Even with sleepy eyes, Izuku manages to flash one of his brilliant, sunshine smiles. Shouto feels it like a hot flash; the usual fondness is there, but with it comes something else that he’s trying very, very hard to ignore. He wants to taste that smile, drink it down.
“Goodnight, Shou.”
Minutes later, Shouto leans against the back of the bathroom door to unzip his uniform. Shower already running, the small washroom starts to fill up with steam, but he rests against the door a minute longer before he can will himself to work the fabric down from his shoulders.
Shouto places his left hand over his abdomen like a gentle heat pack, trying to settle his stomach, to relieve the deep ache that coils downward before radiating outward to his limbs. He still feels too hot for his liking, feverish, but there’s relief in it, too.
He finds the ache is worse and worse the lower down he goes.
Shouto peels his uniform away, freeing his arms and letting it slide down his spread thighs. He’s very hard— unsurprising, except that it’s accompanied by this tension, a helpless wanting, layered over the pain like a dissonant chord.
He considers the pros and cons: he could try and attend to that himself, although his entire hero unit was warned that self-stimulation would not address the particular ‘cravings’ aroused by the quirk, nor would such an orgasm bring more than momentary relief.
Sounds like a bad idea, then. The short-lived relief of Izuku’s supportive touch had only made the quirk’s effects feel worse when they inevitably returned, redoubled for a full-force impact. Not an experience he looked forward to repeating.
No jerking off, then. Shouto grits his teeth.
It was going to be a long couple of days.
In the morning, Katsuki is in the kitchen when Shouto finally rallies enough to experiment with leaving his room. Izuku has been gone for hours and, for once, that seems like a good thing.
“You look like hell.”
Shouto huffs. He feels like it, too, but he’ll manage. “Good morning to you, too.”
Katsuki grunts in answer, neither confirmation nor denial. He stirs his coffee and then gestures idly with a teaspoon. “You get your shit rocked last night?”
No, and yes. Neither answer feels honest and he has no intention of getting into the details, so Shouto settles on, “I’m fine.”
Or he thought he was. Then Katsuki rolls his shoulders, stretching into his back muscles in a familiar racerback tank top, and the way his muscles shift beneath the stretched-tight fabric has Shouto facing the music. He’s woozy at just the sight of him.
Of course Katsuki is attractive. Objectively, and to Shouto in particular. It isn’t a surprise, but it turns out knowing it’s true and feeling it like a sucker punch are two entirely different things.
“‘Fine,’ my ass. I know you got home late. Your patrol shoulda been over long before that.”
Shouto meets those red eyes in an act of defiance. It helps him stall a little, too; he’s still figuring out how much he should say.
“There was an incident downtown. Everyone had to be cleared to leave the scene.”
Katsuki narrows his eyes. “So did you get fucked up, or what?”
“Nothing I can’t handle.”
“Right.” Katsuki doesn’t buy it, but he plays the long game and lets it drop for the moment. He’ll leave Shouto alone at least until he’s had some much-needed caffeine, and maybe by then Shouto will have some kind of a plan.
“Go sit.”
“Hm? Oh.” Shouto catches his meaning, even through the mental fog. He can see that Katsuki is already steeping Shouto’s tea and is topping up a mug of black coffee for himself. It’s a well-orchestrated maneuver, like Katsuki was expecting Shouto to stumble sleepy-headed from his bedroom any time now. “You didn’t need to do that.”
“I don’t have to do jack shit,” Katsuki grits out, annoyed. There’s something expectant in his gaze. “Go on, idiot, before you gotta reheat it yourself.”
Right. Sitting down sounds… good, actually.
Shouto makes his way over to the sofa with Katsuki on his heels. It’s at least a little effort not to show that he’s in pain, taking care not to move stiffly or wince as he walks. Once he’s settled, Katsuki hands off his tea and then curls up with a magazine at the other end of the sofa.
Shouto sips from his mug, trying his best to relax. He’s uncomfortable all over and he hardly slept, but all the more reason to take it easy and do nothing for a while.
He doesn’t always get to have mornings with Katsuki. Sometimes it’s Shouto and Izuku whose schedules line up; other times Shouto is the one leaving early for a shift. Even more rare are the days they all have off, when Katsuki cooks a big breakfast and drags them both on a hike or some other ‘productive’ leisure activity.
But these mornings, Katsuki mornings, are special in another way. Shouto attributes this mostly to Katsuki himself, who always seems especially relaxed after sleeping in. It’s an activity he only allows himself on mornings when Izuku leaves the bed before day breaks. Shouto, for his part, isn’t one to disturb the peace, and so a quiet, cozy atmosphere takes hold and lingers over them until the sun is high in the sky. Any activity the day holds can be done later, when they’re good and ready.
Shouto likes to sneak glances of the expression Katsuki wears while he catches up on his reading: quiet, thoughtful, but not too serious. At ease. It’s a private thing, once again, something the world doesn’t see— because they don’t get to know him like Shouto knows him. Izuku does, of course, but that feels like a given, whereas with Shouto it feels like a strange and generous gift.
It’s on mornings like this that Katsuki might swing his legs around, draping them over Shouto’s lap in the same way he does with Izuku, curling up on the sofa after dinner. Whenever that happens, Shouto can’t help but feel honored. Katsuki is comfortable with him now in ways he never expected him to be.
This morning, however, Shouto feels trepidation. Katsuki sinks further into the sofa, sliding down the cushions, and Shouto has enough sense to worry about what happens when Katsuki decides to close that gap.
He doesn’t do exactly what Shouto expects. Instead of swinging his feet around to stretch over his lap, Katsuki tips himself sideways until he’s resting his head on Shouto’s thigh.
Shouto doesn’t breathe. This is something new— new and exciting, on any other occasion, but right now he’s caught between wonderment and dread.
And relief. It hits him like a morphine drip, not just his leg or his hip but all over his body, deep under his ribs. The comfort seeps into his bones, and it takes an extraordinary effort to not make a single sound.
Shouto doesn’t know where to put his hands. Katsuki seems to notice his hesitation, eying the hand that’s floating uselessly, guiltily, a little above his head.
Katsuki grunts, then he fixes Shouto’s problem (sort of) by snagging his wrist and placing it in his hair.
Soft. Shouto’s heart squeezes. And then his dick does, too, with far more urgency than the ache in his chest and that is exactly what he was afraid of.
He feels Katsuki’s shoulders stiffen up when Shouto forgets to move. He… can’t move. He’s frozen there, with one hand in Katsuki’s hair and the other pressed into the heat of Katsuki’s bare shoulder. He’s caught, cornered, with an ache in his groin, his blood moving south rapidly— too rapidly, making his head spin and his skin crawl with a need he can’t control.
What if Katsuki sees? What if he moves and feels Shouto getting conspicuously hard in his pajama pants? Shameful, wrong. He can’t let that happen. He’ll ruin everything.
“This alright?” Katsuki grits out the words. Annoyed, but concerned now, too, as the moment stretches.
“Yeah,” Shouto lies. He breathes slowly, and makes a concerted effort to trail his fingers through blond hair, feeling the soft strands slip between his fingers. It’s no hardship to do that; he wants to do it. He wants it to be okay, comfortable, normal, just one of the many ways that Shouto has grown closer to Katsuki and Izuku both.
But it isn’t comfortable or normal, because Shouto wants him— recklessly, selfishly, carnally— and that isn’t an impulse that he can allow himself to entertain.
Katsuki didn’t do anything wrong here. It’s Shouto who is making it weird with his unfortunate predicament, worsening by the second. He ought to make some excuse to pull away— but if Katsuki moves now, he might clock it. Shouto needs to avoid that at all costs, for both of their sakes.
“Whatever,” Katsuki says, turning back to the article he was reading and shifting his head on Shouto’s thigh. So close to disaster and yet so far, too far from the place where the contact is most desperately needed. “You can shove me off anytime, you know.”
Shouto doesn’t want to shove him off— and he does, at the same time. He wants to run, and he wants to stay right here. It’s good here. So good, touching him, being touched, holding his weight as Katsuki’s tension unwinds and he seems to grow even heavier in his lap. The feeling fizzes and sparks all along Shouto’s nerves, this overwhelming sense of comfort, pleasure.
Arousal. That’s the part that gives his stomach an ugly twist. Because he shouldn’t be thinking of Katsuki that way. He is off-limits, just like Izuku is. And Shouto is fine with that, he’s been fine with that for years, until this noxious thing in his bloodstream started making every touch loaded, hot, too hot to handle.
Shouto can’t jeopardize what they have. His long-buried feelings are one thing, easily manageable, but this lack of self-control? It’s dangerous. It’s going to consume him.
For each and every weighted second that Shouto lingers— one hand in Katsuki’s hair, another on his shoulder touching bare skin— the pain blooms brighter, hotter. Touching helps until it doesn’t, because it doesn’t move, doesn’t chase the urge. It doesn’t satisfy. He’s painfully aware of everywhere they are not touching— everywhere they can’t, shouldn’t touch, lest Shouto break something he can’t ever hope to fix.
So Shouto burns, sitting with his eyes shut tight and his right hand holding onto Katsuki’s shoulder probably too hard. No, definitely too hard, because first Katsuki shivers, then he reaches up to pry Shouto’s hand away.
“Watch it,” he complains, “before you freeze my tits.”
Shouto cannot allow himself to think about Katsuki’s tits, not if he wants to survive this. He tries instead to get lost in how Katsuki’s thumb kneads into the heel of his palm; Katsuki touching him, knowingly, actively, soothes his nerves long enough for Shouto to focus again— and finally see what he’s done. See that there is frost forming on his fingernails.
Oh.
“You nervous or something?”
He didn’t mean to use his ice; it’s pure impulse to reach for it, a symptom of Shouto trying and failing to quell the dizzying heat that Katsuki makes him feel. He didn’t notice because it didn’t even work, not even a little. If anything, the cold makes him ache deeper into his bones.
Shouto dispels his quirk, whispering, “Sorry.”
“S’alright.” Katsuki circles his thumb again, leaving a trail of heat across his palm. Even through the barrage of sensation, Shouto has enough presence of mind to spot how Katsuki’s brow furrows beneath soft peaks of blond hair. “I’m not trying to push.”
“What?”
“You gotta tell me when it’s too much.”
“I- no, it isn’t that.”
“You’re a shit liar, Halfie.”
Shouto knows that he should answer him, but that isn’t easy to do while he’s throbbing with pain and need— determined to keep it locked down, out of sight. He wants to reassure Katsuki but he can’t find the words.
After several excruciating minutes, Katsuki’s cell phone rings on the dinner table. He grumbles and hops up quickly to retrieve it. It must be Izuku on the other end, a judgment he makes solely from the too-soft note in Katsuki’s otherwise gruff voice, but Shouto doesn’t hear the actual words.
He’s off like a rocket, walking determinedly down the hall and then shutting the bathroom door, gently, but nevertheless with a resounding click. Like a nail in the coffin, he thinks darkly.
Shouto slumps there against the wall exactly where he stood last night— sweating, hurting, wrung-out like a rag— and he makes up his mind.
He can’t stay here. Not today, not like this.
Shouto starts the shower. He makes the water run cold. It leaves him hurting even worse, but ten minutes of ice water is enough to kill even this stubborn boner— hopefully for long enough to make his escape. Shouto stands in the cold spray, shivering more with misery than he ever does from mere temperature. He sluices the sickly sweat away, douses his hair a few more times. His voice almost comes out level when Katsuki calls to him through the door.
“Hey, what gives?” Katsuki asks. “You ran off.”
“I- remembered something,” Shouto calls. “Something I have to do. Today.” He winces. He knows he isn’t good at lying. He doesn’t want to lie, but he can’t afford the truth. “I promised Hanta a favor.”
“Oh.” Then after a pause, he adds, “I’m gonna pretend I believe you.”
Shouto aches, but Katsuki lets it drop. Shouto hears his footsteps fade away down the hallway.
When Shouto emerges from his bedroom twenty minutes later, he’s dressed in the kind of outfit he’d wear trying to be inconspicuous: a hoodie, tan chinos, and a baseball cap pulled low over his eyes. If he’s going downtown, he doesn’t want to draw too much attention from the public.
He also has a backpack with a couple of manga volumes he’s been meaning to return to Hanta. He just got back text confirmation that Hanta is indeed free that afternoon if he wanted to stop by. It was the only excuse Shouto could fashion in a hurry, and the backpack doubles as... insurance. In the case of inconvenient erections, hold backpack low and tight across your lap—
Katsuki glances up at him from the sofa. His red gaze is sharp, but then it softens on contact and that’s the only reason Shouto can meet his gaze without going up in flames.
“That’s mine, idiot.”
“Oh.” It’s true that the hoodie belongs to Katsuki. He loaned it to Shouto days ago and he’s been hoarding it ever since. It was a foolish choice now when Shouto knows he’s already acting weird, but that’s probably why he reached for it— taking comfort wherever he can.
Katsuki doesn’t look mad about it. His frown slips, eyes crinkling at the corners, and he shakes his head to clear whatever thought came with that soft look.
“You running errands, then? Need any help?”
“No, I, um.” Shouto inhales slowly. “It’s something I have to take care of on my own.”
“A manga emergency, then? Tch, whatever.” Katsuki raises his hands in mock surrender. “Just get your ass back here for dinner. Izuku will cry if you don’t.”
It’s a bit of a running joke, since Izuku will cry at the drop of a hat, but Shouto thinks of it as a form of code. Shouto knows who will actually be disappointed if he misses dinner, the same someone who’s currently avoiding his eyes.
“I’ll be back. I promise.”