Work Text:
There’s a soft knock at the door. A sound Katsuki is plenty familiar with.
“Go away,” he groans, shifting against his mattress underneath the covers.
His pillow chafes against his cheek, and everything is so uncomfortably hot, but the thought of not being surrounded by the blanket he stole from Izuku’s room makes him shudder. It still smells like Izuku—his alpha. The mating bite on Katsuki’s collarbone stings sweetly from the sound of his name whispered in Katsuki’s head, and the burning ache between his legs grows. Katsuki didn’t even know it could. Didn’t know how much he’d come to rely on Izuku being here, until he isn’t.
The door squeaks on its hinges, and Katsuki cracks an eye open to Shouto’s half-and-half head poking through the crack.
“Katsuki… Can I come in?”
He doesn’t wait for Katsuki’s response. For fuck’s sake.
Katsuki can’t bring himself to be mad though. He’s loath to admit it, but he feels more at ease with Shouto’s scent close by.
Shouto kneels on the bed, hands hovering over Katsuki’s curled up form like he’s not sure if he’s allowed to touch.
He is, but he doesn’t know it yet. Katsuki doesn’t have any plans to let him in on that secret anytime soon either.
It’s…too much. They’re good as they are. Shouto is just down the hall, occupying the room next to Izuku’s, and they eat together and work together and shower together in the locker room afterwards. Katsuki’s not about to make it weird.
“You’re feverish,” Shouto says. “Let me help you.”
Fuck. This wouldn’t—
This wouldn’t even be happening if Deku was here and doing his damn job.
Shouto’s hand is icy cold against Katsuki’s neck as he tries to pry the covers off. Katsuki shivers, clutching the sheets harder, and twists his head to bite down on Shouto’s fingers.
“Ow,” Shouto says, tone flat. He sighs and gives up, then lies down in the empty spot behind Katsuki, above the covers.
He presses his forehead to Katsuki’s neck. And.
God, does it feel good to cool down.
Katsuki’s too busy trying not to sigh in relief to protest Shouto’s right arm wrapping around his body and pulling him closer, but…it feels too good to complain. He can’t. Surrounded by Shouto’s sweet herbal scent and cooled down by his quirk, he can finally breathe again.
This close, Katsuki can pick out the faint scent of honey that Shouto carries on his skin, mixed with something darker and earthy and endlessly soothing. Shouto smells like the tea Yaoyorozu liked to brew late at night back when they used to live at the dorms, and fuck if Katsuki hasn’t developed a taste for it.
Tension slowly seeps out of his shoulders, then rushes back in when he feels Shouto’s lips press to the back of his neck.
“Uh.”
Shouto hums, murmurs against his skin, “Is this okay?”
Is it?
Katsuki’s spine tingles from Shouto’s soft closed-lip kisses.
Shouto tugs at him with his arm until Katsuki gives in. Uncurls from his fetal position and lies on his back, wincing from the body aches.
Climbing over him, Shouto presses their cheeks together. His right to Katsuki’s. It feels so good on Katsuki’s heated skin, and he lets Shouto pull away the covers and blankets from between their bodies. He doesn’t need Izuku’s scent as bad with Shouto close by.
“It’s okay,” Shouto whispers. “I know what it’s like.”
He does, doesn’t he? They both go through this.
It’s just that…Katsuki hasn’t felt it this badly for months now. He’s gotten too used to being taken care of properly, by an alpha, taking a knot. It’s ridiculous how much it helps. It’s ridiculous how much Katsuki’s come to rely on it.
On Izuku.
How does Shouto do it? He doesn’t let anyone touch him.
Katsuki knows Izuku wants to. He hides in Katsuki’s room when Shouto goes into heat.
“I can’t smell him like this, Kacchan. I don’t know what I’ll do.”
Go feral, probably.
Katsuki usually keeps him distracted for a few days until the worst of Shouto’s heat is over. And Shouto spends his heat acting like nothing is out of place. Like he isn’t in incredible pain, or in need of alpha dick.
Katsuki doesn’t get it.
“You deal with it fine,” he mumbles.
Shouto stills and pulls back to lock their gazes. Takes a look at Katsuki’s embarrassingly blotchy face and smiles.
Even his smile is stupid. He can’t even smile properly; it’s just a flat line. But Katsuki can tell because his eyes crinkle ever so slightly in the corner.
“Because you’re here—both of you.”
As if that’s an explanation. What.
Katsuki’s cooled down enough that he can actually think now. And, regrettably, pay attention to what’s happening.
Like how fucking close they are.
Their bodies are flush together, and a part of him worries Shouto may be able to feel the slick running between Katsuki’s legs and dampening his underwear.
He’s not wearing any pants because the texture was bothering him—he chucked them somewhere across the room.
He internally curses himself because if Shouto looks down he’ll see.
He’ll see, and Katsuki will disintegrate.
His smile is disarming. Warmth pools in Katsuki’s belly at the sight, and he really doesn’t need more of that right now, but he can’t help staring.
At Shouto’s lips and his mouth. At his pretty, pretty eyes. Soft hair. Soft skin. Everything about him is soft.
His scent, especially so. Katsuki breathes it in, and his heart stutters knowing his nest will be laced with it, with the perfect bittersweet concoction that is so uniquely Shouto. Until he does his laundry and changes his sheets.
He doesn’t want to.
“Can I kiss you?” Shouto asks.
And this time he actually waits for an answer, blinking patiently while Katsuki rearranges the words in his head to make them make sense.
“Y-yeah.”
His voice cracks on the syllable, and he clears his throat and closes his eyes because he can’t bear to look into Shouto’s.
It’s so unfair.
The kiss is so painfully soft that Katsuki sighs into it. Their lips slot together, and Katsuki lets himself indulge in Shouto’s mouth, lazily exploring. He can almost taste the tea leaves and honey that make up Shouto’s scent.
As he relaxes, his hands find their way around Shouto’s torso and his shoulders, one burying itself in his silky hair. Katsuki can’t believe it took them this long to kiss.
He can’t believe that they’re kissing at all.
Feels like a fever dream.
Well. Doesn’t matter.
Shouto’s mouth is hot, and so is his left hand, skimming across Katsuki’s stomach underneath his tank top, dangerously low.
Katsuki whines and aches for more, his legs wrapping around Shouto’s waist involuntarily.
To get him closer, closer, closer.
“You’re wet.”
Fuck. Fuck.
Shouto’s hand comes up to squeeze at his shoulder and brush against his jaw. He noses Katsuki’s cheek and kisses the corner of his mouth. So, so gentle. Katsuki doesn’t deserve it.
Any of it.
“It’s okay,” Shouto says. “I’m going to touch you.”
Forming words is beyond Katsuki now. All he can do is gargle out a choked up noise that Shouto steals off his lips easily.
He licks at Katsuki’s neck, his swollen scent glands, at the same time as he slowly pulls at the cotton fabric of Katsuki’s underwear. Katsuki cries out from how sensitive it is to be touched in both places at once.
There’s a mate bite low on his collarbone from his alpha, and most of the time Katsuki feels protective of it. Makes sure to keep it hidden and secure.
It’s different now. He shoves the strap of his top off his shoulder and pulls it down enough to expose the site. And then he directs Shouto’s mouth to it. To kiss and touch and lick.
Whatever he wants to do. It’s his. Katsuki’s his.
Fuck.
This. This is why he can’t do this.
It’s why he couldn’t do it with Izuku either. Katsuki can’t do casual. The first time Izuku fucked him, before they even talked about anything, before they even kissed, Katsuki pushed Izuku’s head into his neck and begged and begged and begged for a mark. Like a man possessed. Pathetic.
So, so rejected when Izuku wouldn’t do it.
The only reason he recovered from that was because he and Izuku went a week without talking until Izuku realized that it wasn’t just a spur of the moment thing. That Katsuki meant it. And he gave Katsuki what he wanted.
Apologized so much.
“I’m sorry, Kacchan. Of course, I want you. I didn’t know. I didn’t know it was real. I’m sorry.”
It’s stupid looking back, but it was the worst week of Katsuki’s life.
He can’t go through that again.
Not that Shouto can even give him a mating bite. But.
A trembling breath escapes Katsuki’s lungs without permission. His eyes sting. Pathetic, pathetic, pathetic.
Shouto senses it. Looks up and into Katsuki’s eyes like he can read him.
“What’s wrong?”
So much. Everything. Katsuki can’t tell him that if they keep going, he can’t go back to how it was before. Can’t go back to just being friends and roommates and nothing more.
He can’t know the feel of Shouto’s mouth on him, his fingers, every speck of colour in his pretty eyes, and no longer be allowed to touch.
Sitting here, naked but for a flimsy tank top that’s riding half-off, an exposed nerve. Throbbing and waiting to be uprooted.
A warm hand settles on his cheek. Lips to his temple.
“Katsuki.”
He can’t say anything, so choked up. If he tries, it will all burst out of him. Ugly and burdensome and too much.
“Katsuki,” Shouto tries again. “Tell me. I’m not going anywhere.”
He’s so unfair. How can he go around saying all this. Touching. Kissing. Scenting Katsuki’s clothes to smell like him because he likes to steal Katsuki’s oversized hoodies. Eating Katsuki’s food and giving him that soft smile and saying thank you like no one else has ever made food for him before. Lying with his head in Katsuki’s lap and taking a nap without a care in the world, like he knows Katsuki will take care of it. Him. Everything. (He will.)
“I—”
That’s all that makes it past the lump in his throat. His eyes leak, and he turns his head into his pillow to hide, but there’s only so much he can do with Shouto’s weight on top, pressing him flat into the mattress.
Shouto bites down gently on his earlobe. Then, “Tell me.”
Katsuki needs to do something with his hands. One of them is still around Shouto’s back, and with the other he claws at the bedsheet underneath, making patterns that make no sense but at least keep his sweaty hands from exploding something. Something important like the All Might card he keeps under his pillow.
Or something precious. Like Shouto.
Which makes it extra annoying when Shouto doesn’t let him. Takes his hand and links their digits together. His are longer, Katsuki’s more calloused. But they fit perfectly together, which only serves to make Katsuki cry harder.
Shouto waits patiently and soothes the ache with unasked-for-but-deeply-needed kisses that Katsuki doesn’t know how to thank him for.
When the volcano in his chest dies down, Katsuki says, “I—I can’t lose you.”
He catches Shouto’s frown in his periphery, accompanied by a squeeze where their hands are still joined.
“You won’t. I’m not leaving.”
That, Katsuki knows. That’s not the problem. Shouto’s been his friend longer than Katsuki’s wanted him to be, and he’s never strayed far, not even when Katsuki’s pushed him. That’s not what Katsuki’s afraid of. He can’t say the real thing, though.
Doesn’t know how. Doesn’t know if it’s something that’s even allowed.
How do you tell someone that you’re afraid of losing a version of them that you’ve never even been entitled to?
Yeah.
Katsuki’s done it once. With Izuku. Except that was easier because it was Izuku, and he never had to say it so much in words because even at their worst, they have always silently understood that they’re more to each other. In a way that no one else could ever be. In a way that is bigger than them, than their problems.
That’s not—
That’s not how he is, with Shouto. Everything about Katsuki is gently muted when Shouto’s around. Swimming in cool water with waves lapping around to caress his face.
It’s everything. How can Katsuki go around asking for more? Asking for—this?
They’re still so close. Makes it easy to pretend Shouto actually wants this beyond his hero complex. Beyond his sense of duty to help his friend in need, or—or whatever it is that’s happening here.
Katsuki is feverish and chilly at the same time, and he can blame that on his heat or Shouto’s quirk, or the tangled mess of his feelings, but it makes it so damn hard to think straight.
“Why are you doing this?” he asks.
“Wha—”
“No, don’t answer that. I don’t wanna know. It fuckin’ sucks, you know? You can’t just—come in here and do whatever you want. Kiss me and touch me, and then go back to pretending everything is normal. Do you even know how hard it is? I try not to want you, but you’re always so damn close, and you smell good, and you’re so fucking oblivious—mmph.”
Shouto’s mouth muffles the rest of his rant. Not that Katsuki had anything important to say. He was just…finally letting it all out. All his frustration. His want.
This kiss puts the previous ones to shame. Shouto licks into his mouth like a man starved, and Katsuki lies back, lax, and lets it happen. Lets his wrists be pinned above his head onto his pillow.
Shouto grinds his thigh between Katsuki’s legs, and Katsuki’s still so out of it, he’d almost forgotten how sensitive he is. His hips jump up at the contact and chase the friction of Shouto’s pants again.
Shouto pulls back to say, “I want you too. All the time,” and it lights a part of Katsuki’s brain on fire while snuffing out the anxiety.
Oh, hell.
“Izuku?” Katsuki asks, because he needs to know. It won’t—it won’t work, without him.
Shouto breathes out softly, a soft smile gracing his lips again. “Of course. It was him, before anything else. Before I even knew anything about anything. But he was always yours, wasn’t he?”
“He wants you,” Katsuki says.
That, Katsuki is sure of. It’s easier to confess secrets that aren’t his own; satisfying to see Shouto’s eyes widening in surprise as he takes in the information.
Does he really not know how loved he is?
Katsuki tugs his left wrist free and pushes Shouto’s head down onto his collarbone again. His bite mark is buzzing with sensation already, stimulated from his heat and how aroused he is.
“He’d give you one just like it if he could,” Katsuki says.
That prompts Shouto into action. He licks around the mark, and Katsuki hisses. One more time and Katsuki moans. He cards through Shouto’s hair with his free hand and imagines doing the same thing while Izuku fucks him. Watching their bodies fold into each other like they were meant to be. Watching Izuku mark Shouto’s skin. His territory. Their omega.
Izuku’s coming back tomorrow, and even that feels like too long of a wait.
It’s sickening, how much Katsuki wants it. The thought of it is enough to make him slick, and he squeezes his legs around Shouto’s thigh, so that he feels it too.
Shouto gasps into his chest and climbs back up to pin both of Katsuki’s hands down again.
“Stay,” he says before letting go.
Then he crawls down. A kiss to Katsuki’s throat, another to his sternum. He pushes Katsuki’s tank top as high as it goes to lick and kiss his stomach as he makes his way further down. Excitement builds in Katsuki’s belly, cheeks uncomfortably warm with the anticipation of what’s about to happen.
Shouto runs a gentle finger along Katsuki’s inner thigh, and Katsuki shivers, legs dropping open to make space for him.
Leaning down, Shouto’s face disappears from view, leaving only his half-and-half head for Katsuki to see, and his mouth finds its target. The sound Katsuki lets out is inhuman, thighs spasming out and only kept down because Shouto’s hands, one hot, one cold, won’t let him move out of place.
Another lap of Shouto’s tongue, and Katsuki can’t help it. His hands fly down into Shouto’s hair to push his head closer, inside, he needs something inside now.
But Shouto does the opposite. Comes up and gives him a look.
His hand traces a circle onto the crease of Katsuki’s hip, and he says, “Told you to stay.”
Fuck. Katsuki retrieves his hands and obediently puts them above his head again.
“Good. I know you can do it.”
Katsuki’s cheeks heat up further, and he turns his head into his pillow to hide half of it.
It earns him a kiss, a centimetre off of where he wants it, and then Shouto’s fingers dance around his hole, gathering slick before slowly entering. So, so agonizingly slow that Katsuki almost brings his hands down again to finger himself. Show him how it’s done.
It’s not as good as a knot, but Shouto’s fingers heat up and cool down, and he uses his mouth at the same time, while his free hand rubs patterns on his hip, achingly soft.
Katsuki’s dizzy with it. With all his want, laid bare, and Shouto taking it all in stride and giving it back tenfold. Katsuki wants to touch him too. Wants to know what it would feel like to kiss him in secret places and watch his face twist with pleasure.
What it would feel like to fuck him and have Izuku watch.
Katsuki comes with a small gasp, vibrating under Shouto’s touch, and Shouto doesn’t pull away until Katsuki’s done riding the wave. His mouth and fingers are a mess, and Katsuki sits up to take his tank top off and wipe him clean with it.
The clarity, the break in his heat-fever, has him trembling with anxiety again, not that he’ll admit it. Everything is okay, but the weight of their conversation dawns on him.
There’s no going back from this.
Shouto must realize it too. He lies on top of Katsuki with his full weight, warming him up this time instead of cooling him down. Katsuki tugs at his shirt until he sits up to pull it off before settling back down, skin to skin.
Feels too fucking good. Unreal.
And Katsuki dozes off with his head buried in Shouto’s crumpled up shirt, breathing in his honey-tea-leaf scent.
-
When he wakes up next, he can tell his heat is over, body no longer aching in places he can’t reach.
Shouto is nowhere to be found, and Katsuki panics momentarily before finding a sticky note taped to his chest that reads, “I’m taking a shower,” with a smiley face. It’s so stupid and dorky, and so, so Shouto.
Katsuki is also in desperate need of a shower, but they only have one bathroom, so he rolls over and picks up his phone from the nightstand to distract himself while he waits.
His lockscreen makes his chest pang. It’s a picture of Izuku in his hero costume, smiling so hard that his eyes are closed all the way through.
Katsuki’s body is no longer screaming for his alpha, but his heart still crumples at the sight of his Deku.
Missing him.
‘Course he does. Katsuki’s not above admitting that. Hasn’t been for a long time.
There’s so much that he needs to tell him.
Katsuki calls the first number in his speed dial.