Thread by @atsumusbiceps

skts, nsfw, omegaverse, omega!kiyoomi, alpha!atsumu, possessiveness, heats @HQomegaverse #hqomegaverseweek2022
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Kiyoomi knows he and Atsumu are just fooling around. He knows Atsumu just gets off on getting to fuck a big omega like Kiyoomi. It has to do with his horrible ego. +

Kiyoomi knows the past few months have been casual hook ups, he /knows/ they aren't serious, so he also knows that it's probably a horrible mistake to call Atsumu when he's deep in his heat, desperate and sweating in bed with his largest dildo shoved firmly inside him. +

He's always been able to get through his heats without an alpha to help him through it. It's what he prefers. The last thing he wants is inflating some alpha's ego by being so desperate for them during his heat. Multiple that by a thousand when it comes to Atsumu. +

Part of Kiyoomi already knows that he gets too lost in pleasure when he's with Atsumu that he's prone to saying some stupid shit. It's just that Atsumu seems to push every one of Kiyoomi's buttons in a way that gets Kiyoomi's off embarrassingly fast. +

So that's why Kiyoomi wanted to hole up in his apartment and avoid Atsumu like the plague the first time he went into heat since they started hooking up.

It's when Atsumu answers on the third ring that Kiyoomi cheeks burn with shame and he realizes the severity of his mistake. +

"Hey?" Atsumu answers, sounding confused. They don't really talk on the phone, because it's fucking /casual/, Kiyoomi reminds himself, so Atsumu's confusion is vastly warranted. When Kiyoomi doesn't answer, he hears Atsumu ask, "Omi?"

"Atsumu," Kiyoomi says, throat tight. +

There's a long pause, and Kiyoomi squeezes his eyes shut in embarrassment. Fuck. Atsumu's smarter than Kiyoomi gives him credit for. He must register that Kiyoomi sounds...affected.

Atsumi's voice is lower when he finally says, "What's up?"

"I-" Kiyoomi inhales sharply. +

He's mortified. Mortified that just the husk in Atsumu's voice is making him wetter as he squeezes around his dildo.

Still, he just wants- he- he needs-

"Can you come over?" Kiyoomi grits out.

Another long pause before Atsumu responds.

"Right now...I mean...are ya sure?" +

"No, but-" Kiyoomi takes another breath. "I just- I'm-"

"Yer in heat," Atsumu says. And Kiyoomi finally hears it, that smug tone coloring Atsumu's voice.

Kiyoomi wants to hang up. He should definitely hang up. But he's too worked up and needy to think clearly. +

"Shut up," Kiyoomi still snaps. "It's not...it's not a thing. You're just convenience."

It's a mean thing to say. Well, to anyone who isn't Atsumu. Because Atsumu just chuckles and says, "Sure. Shit, Omi-kun. Ya need yer alpha there to help ya through it, huh?" +

"You're not my fucking alpha," Kiyoomi spits back, but something about Atsumu's words make Kiyoomi slightly delirious. Kiyoomi knows it's all dirty talk to Atsumu, that there's no way Atsumu seriously thinks Kiyoomi wants him to come over to...to mate with him. +

Plenty of omegas use alphas they aren't mated with to help them through their heat. Can't Atsumu just keep it at that? It would certainly make Kiyoomi think clearer.

"Hmm. I don't know. Maybe I'll come over if ya ask nicely."

/If you beg/ Kiyoomi hears. +

"No. Come over or don't. I don't care."

"Doesn't sound that way. Sounds like ya really want me to come. Ya wouldn't have called if ya didn't."

"You're being a dick. I'm hanging up."

Kiyoomi starts to move his phone when he hears Atsumu says, "Wait."

"What?" +

"Fuckin' relax, Omi-kun. I'll come over."

"Seriously?" Kiyoomi asks, not convinced.

"Yeah," Atsumu says. Then, even lower, "Yeah. I know what ya need. And I know you do too. Or, like I said, ya wouldn't have called. I like hearin' ya like this, baby." +

Kiyoomi feels shameful again. He hates that Atsumu used the word "need" because it's dangerously close to the truth. He hates that he acts like a fucking idiot around Atsumu, and Atsumu loves it.

Kiyoomi hates it so much, so he says, "Fuck you," and hangs up. +

Still, Kiyoomi's relieved when there's a knock on his door 30 minutes later. He's naked, so he grabs the largest blanket on his bed and wraps it around himself. As he walks to his door, he realizes how he must look. His curls are messy from sweat, and his cheeks are flushed. +

But he feels slightly too feverish to care, even when he nearly trips over his blanket in his haste to get to the door. He opens it and his met with Atsumu's entirely too smug presence. Atsumu looks too good in his dark button down and with his styled hair. +

Atsumu shamelessly checks Kiyoomi out, his smirk ever present. "Jesus. Look at ya."

Kiyoomi glares at him, a lump forming in his throat at how embarrassing it is to let Atsumu see him so...desperate.

Still, Atsumu's eyes start to glaze over. "Ya reek, Omi-kun." +

Oh. Kiyoomi hadn't thought about that either. Normally when they fuck Kiyoomi still wears his scent-blocking patches. Anything to put more distance between them even when Atsumu's dick is up his ass and their words border on something too intimate for just a casual fuck. +

Now, Kiyoomi's sugary scent is more overwhelming and burnt-smelling than ever. Kiyoomi's stomach rolls at his own thoughtlessness. As if sensing it, Atsumu adds, "It's good. Let me in?"

Kiyoomi ears burn, but he ignores it, letting Atsumu in and shutting the door behind them. +

He feels shaky and brimming with nerves as he leads Atsumu to his bedroom. He still hasn't said a word, but he suddenly doesn't trust himself to speak. Especially not when Atsumu spots Kiyoomi's dildo on his nightstand and his own strong whiskey scent rolls off of him. +

Atsumu looks at him, pupils so dilated that his eyes are nothing but golden rings. Despite his heated gaze, his words come out condescending.

"That thing wasn't enough for yer needy ass, huh?"

"Shut up," Kiyoomi mutters, but he's already leaking at those words. +

They stare at each other for a moment. Kiyoomi's own heart is thumping erratically in his chest. And then the next moment one of them kisses the other. It doesn't matter who started it, because suddenly it's a mess of lips, and teeth, and tongue, and moans. +

It's 0 to 100, like it always is with Atsumu; teasing words to nasty dirty talk; gentle touches to bruising grips. Kiyoomi hates it; Kiyoomi lives for it. While Kiyoomi detests feeling like a desperate mess, /fuck/ it's flattering when Atsumu's just as eager. +

And maybe that's why Kiyoomi continues to find himself in this situation, with Atsumu braced over him, two fingers steadily thrusting into him. Because Kiyoomi is the one getting fingered, but Atsumu is the one breathing too hard as if roles were reversed. +

"Jesus, shit," Atsumu grunts into Kiyoomi's skin, his nose pressed right against Kiyoomi's throat. "Keep moanin' my name."

"Atsumu," Kiyoomi gasps, slipping into that dangerous haze where his words are involuntary and- and- "Fuck me, fuck me." +

Atsumu groans, sliding another finger in. The squelching noises of Kiyoomi's slick is disgusting, mortifying, and cause Kiyoomi's entire body to feel like a fire is scorching through him. And yet, he's so turned on it hurts. He needs Atsumu. /Needs him/. +

"Shit, baby," Atsumu says, that shitty petname Kiyoomi hates slipping out again. Kiyoomi squeezes his eyes shut, tears slipping out at how much he doesn't want to love it.

And it's so much worse now that Kiyoomi's in heat, because now he really wants to keep hearing 'baby'. +

"Fuck me," Kiyoomi pleads again, one hand bunched in his sheets and the other gripping Atsumu's hair so hard it has to be painful.

"Ask nicely," Atsumu commands.

"N-no," Kiyoomi gasps when Atsumu's fingers scissor inside of him, trying to hang onto a thread of his sanity. +

Kiyoomi downright /whimpers/ when Atsumu withdraws his fingers completely, leaving Kiyoomi empty and unsatisfied.

"/Beg/ me," Atsumu growls, licking Kiyoomi's salty skin at the most sensitive part of his throat. "Beg yer alpha for his knot. The only fuckin' knot you ever need."

At those words, it's like a flip has switched and Kiyoomi wants to be so good for him. Kiyoomi wants to be /enough/ for him. It's a bone deep, innate need. Kiyoomi's so far gone he doesn't even remember a time when he's wanted anything different. It's shameful; it's delicious. +

Kiyoomi's crying, he knows he is, but he wants to be so fucking good for his alpha.

"Please, please, need you, /please/," Kiyoomi slurs, sweating and sick with want.

Atsumu curses again, then shifts around. Kiyoomi eyes are still closed when Atsumu finally thrusts his dick in.+

Kiyoomi gasps, scratches his nails up Atsumu's back, holding on for dear life as Atsumu sets a devastatingly brutal pace.

"Fuck yeah," Atsumu groans, pressing one of Kiyoomi's thighs into the bed to keep a good angle, his fingers digging painfully into his skin. "I like that." +

"Like hearin' ya so fuckin'- /shit/- so fuckin' hot for me."

"Atsumu," Kiyoomi begs, but he's not sure what he's asking for. He just wants Atsumu closer, deeper, faster, until he's everything; everywhere; all-consuming; his /alpha/. +

Kiyoomi's head is spinning as his headboard bangs against his wall. It's filthy how the room smells like sex, and slick, and their scents. It's filthy how Kiyoomi whimpers with every thrust and Atsumu just fucks him harder. It's too much; it's not enough. +

Atsumu's voice takes on a slightly panicked tone as he demands, "Tell me how good it feels. Tell me how I'm the only one who fucks ya like this. Tell me ya want only me. Just- /fuck/- just me."

And there it is, that dangerous dirty talk that keeps Kiyoomi up at night. +

He wonders where dirty talk ends and naked truths begins. He wonders when he started hoping he could have both.

"Feels so good, oh my god," Kiyoomi moans, his voice wet and sticky. "My alpha, yes- yesyesyes-"

Atsumu growls again, his teeth grazing Kiyoomi's scent-glands. +

For the first time, Kiyoomi wishes he would just bite and claim him already. He wants it- he wants all of it- wants it so deeply he wonders how he can feel so strongly for Atsumu when it's just supposed to be /casual/. +

But- some part of Kiyoomi knew it wasn't casual when he dialed Atsumu's number. Not when Atsumu has started to consume all of his thoughts. Not when Atsumu's the only one who pushes all the right buttons. Not when Atsumu fucks him so good he's ruined Kiyoomi for anyone else. +

Not when Atsumu pushes his knot firmly into Kiyoomi's ass and Kiyoomi comes harder than he ever has in his entire life.

"Atsumu, yes, yes!," Kiyoomi screams, clinging to him like he never wants to let go.

"M'right here," Atsumu says, kissing him deeply. "M'right here, baby." +

They'll deal with it later, Kiyoomi's foggy brain tries to tell him during the come-down. They'll deal with what it means for Atsumu to do that with him. They'll deal with what it means that Kiyoomi /wanted/ it. +

And Kiyoomi really should've known it wasn't just /casual/ when Atsumu continues whispering soft praises, promising to help build him a better nest, telling him how perfect he is, calling him baby and princess and darling, and Kiyoomi's so high from it he can hardly breathe. +

"I don't want you doin' this with anyone else anymore, Kiyoomi," Atsumu tells him, voice soft but his words laced with a lingering demand. "Only me."

"Only you," Kiyoomi promises easily, because Atsumu's possessiveness pushes the button Kiyoomi never knew he wanted pushed. +

Until Atsumu. /Only/ Atsumu.

It's terrifying, and sickening, and perfect. Kiyoomi wonders how they've spent so long denying what this was, creating distance when they've only wanted to be closer.

He feels Atsumu smile against his skin, and he's ready to keep falling.

/end

so this is technically late but i started a new job and between that and rewriting this like 5 times....well here it is hahaha. this is my first time writing nsfw omegaverse so it's probably not perfect but i'm excited for this fanweek and i hope i somewhat delivered !!

also i have a cc hehe come say hey curiouscat.live/atsumusbiceps