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They knew it was wrong and always felt bad about it afterwards, or at least Osamu did, but they did it anyway because it felt good and as long as no one found out no one was about to make them stop. They were each the one bad habit the other couldn’t kick.
On weekends when their parents were away on business trips or doing whatever they’d lie in bed or on the floor and make out for hours, kisses escalating to bites and roaming hands as the sun sank below the horizon. It always ended in a fight over who’d been too much, too needy, too aggressive--who’d crossed the lines that were unspoken and ever-shifting. They fucked like it was hand-to-hand combat.
Atsumu was the one who’d pressured his brother into letting him do it, always whining and wheedling about Samu giving him blue balls and being a fuckin’ tease, secretly being a whore underneath it all because there was no way he didn’t want it if he acted like that. Like what? Osamu quickly learned to stop asking.
It was Atsumu, too, who crossed the line in the first place. He caught Osamu jacking off, and instead of turning heel like a normal person would and giving his brother a crumb of privacy, he told him he was doing it wrong and said here, watch me. We got the same dicks, right? Stroke it juuust liiiiike this and maybe you’ll stop going around all backed up and uptight like you’ve got a five-foot stick up your ass. They started watching porn together and before Osamu knew it, they were jacking each other off and kissing, because Atsumu was the one with experience and hell if he was going to let his baby bro scare off his first date by shoving his tongue down her throat. Except Atsumu did that, too, but it was okay if he did it, because it was okay if Atsumu did pretty much anything. Atsumu had a mandate from heaven to take what he wanted and he made sure everyone around him knew it. It was only thanks to his mercy that Osamu had made it out of the womb.
They didn’t use condoms because they’d be dead meat if their parents found any evidence of what they did, but that was just an excuse. Osamu knew Atsumu liked it better that way. And him? Well, he wasn’t sure. He liked getting off, that was the thing.
He didn’t like that Atsumu drove him to such distraction that his grades were slipping, but that was his own fault for being so damn weak. He made up for it by biting Atsumu’s lip and slapping him away when Atsumu got a little too bold, sliding his hands up Osamu’s shirt and pinching his nipple while the other rough palm squeezed the meat of his pec.
“Ow,” Atsumu complained though Osamu hadn’t even put his back into it, wincing and cupping the abused spot on his face. Atsumu still had a bruise on his cheekbone from their fight last week. A rare rugged touch to his pristine pretty-boy features, and it was sexy as hell and knowing he was the one to put it there made Osamu throb. “You’re being a real bitch today, you know that?”
“You get your fuckin’ hands off me. Stop that shit.”
“What, don’t like getting your tits played with?”
“Don’t call ‘em that.”
“Why not?” Atsumu purred. He lurched over Osamu’s body, pinning him with a stare and both fists planted into the mattress. A slice of late afternoon sun cut across his face, turning his irises amber. “Don’t wanna cum too soon?” He shoved his knee up into Osamu’s crotch, hard enough to hurt, and Osamu’s dick twitched anyway. “Damn, you’re so easy…”
His evil smirk slipped and he dipped to kiss Osamu again. Osamu’s lids drooped and his mouth fell open to welcome it. Atsumu’s knee didn’t budge an inch. He ground tight circles over the bulge in Osamu’s sweats, coaxing his erection into filling out, wetting the fabric with precum. Without warning, Atsumu shifted and fitted a palm over it, squeezing him through his clothes, and Osamu broke the kiss to let out a moan.
Atsumu answered with a breathless laugh. “Whore,” he teased.
Osamu snapped his lips shut and forced a glare, irritation flaring up amidst the desperate, coiled arousal that threatened to burn him alive, but hell if he’d let Atsumu know that. His tongue was thick in his mouth, his addled mind slow to conjure up a response. “Cunt.”
Atsumu lifted a brow. Snorted like it was funny. The irritation surged hotter in Osamu’s gut and he decided that this was too much humiliation to bear; he sat up at once, knocking Atsumu away with a harsh jerk of one knee. “Oi!”
Osamu threw an arm around Atsumu’s shoulders and used the five or six pounds of advantage he had to roll them right off the bottom bunk, thunking cacophonously on the wooden floor three feet below, Osamu on top for a brief moment before he sprawled out beside his twin.
Atsumu swore in pain, eyes closing as he cringed into fetal position. “You fuckin’ idiot,” he hissed.
For Osamu, the five second delay before Atsumu got himself back in action was enough. He shoved his brother onto his back and braced a forearm across his shoulders, the bulk of his bare arm just teasing his windpipe. Atsumu’s eyes flew open, then narrowed. His breath came fast and shallow. Osamu just tightened up his lips and pressed down harder, rolled his hips to feel Atsumu’s identical erection, curved so the swollen head of it peeped out the waistband of his shorts. His shirt was rucked up, showing off his abs all tensed and ready for a fight.
Osamu’s mouth watered. Atsumu’s hard look was a shot of pressurized steam up his spine, getting him ready to blow.
His lips parted prettily when Osamu rocked their hips together again, and Osamu made the mistake of pressing a thumb to that rosy flesh, entranced and so dizzyingly turned on that he forgot for a moment that Atsumu was a menace who was always, always out for blood. Atsumu sought out the digit and clamped his teeth around it, and Osamu ripped it away just before he could break skin. “Shit.”
The pain throbbed through his hand in a heartbeat, but a heartbeat was all it took for Atsumu to get out from under him, wrenching the arm off his chest and flipping them over with an ungraceful tackle, arms hugged around Osamu’s midsection. Osamu grappled with him blindly, pressing that stupid leer away with a palm over Atsumu’s mouth. Of course he licked it. Osamu let him go on reflex, another mistake: sitting back all smug atop Osamu’s hips, Atsumu finally had him pinned.
Atsumu licked his lips and fitted his hand around Osamu’s throat, tilting his head so his cheek smushed into the floor, tightening his grip like a threat. “Play nice for a sec,” he said. His free hand crept under the hem of Osamu’s shirt, then pulled it up in one go, exposing his torso and pecs that were still sensitive from arousal and Atsumu’s insistent touches. He groped one as before, except now he timed it with a delicious grind down on Osamu’s cock and it felt too good to deny, even if it was humiliating. “They’re so soft, fuckin’ look at yourself.”
Osamu bared his teeth. He couldn’t ease the rise and fall of his chest, or stop the way his cock beat against its confines as Atsumu stared down at him, mesmerized. Atsumu pulled at his nipples cruelly, chuckled as Osamu sucked in a harsh breath and arched ever-so-slightly. “Fuckin’ creep.”
“It’s ‘cause you’re the bitch in this whole arrangement, aren’t cha?” Atsumu said. “Got nice little bitch titties.”
Osamu snarled and grabbed Atsumu by the forearms, shoving him back, off of his body. He fumbled with his shirt, pulling it down as he pulled his knees up, making a pathetic effort to scramble away for the gods knew what. He was still hard, aching for it, skin all tight and riled up and waiting for Atsumu to take this thing out of him. But pride goes before the fall, or whatever, and he wasn’t about to say so.
Osamu got the breath punched out of him as a shove had him colliding belly-first with the floor, chin thudding painfully. Atsumu dug a knee into the small of his back and fisted his hair, pressing him down, smearing him into the floor that was probably months overdue for a good, deep clean. Osamu glared at the invisible particles of dirt, though whether he was any better than them, he couldn’t say.
Atsumu shoved Osamu’s sweats down over his ass and Osamu flinched and jerked his hips involuntarily, rutting his clothed cock into the wood. The waistband dug into the soft backsides of his thighs, framing his ass, and Osamu sensed it coming before it came. Smack. He didn’t have time to tense. Atsumu laughed, breathless with glee. It stung like a bitch and a moment later, before Osamu could recover, he did it again.
“Fuck.”
“Yeah? Want me to fuck your tight little ass? That’s the plan--now stop squirming, we ain’t got all day.”
Atsumu smoothed his palm up over the warm flesh, still jiggling from the impact, and spread him open, thumbing over his sensitive cleft. A shiver rippled down Osamu’s spine.
“Open wide, Samu.” This was all the warning Osamu got before three fingers were prodding at his mouth and forcing themselves inside. “Get ‘em wet because that’s all you’re getting.”
Osamu grazed his teeth over them, just enough to threaten, and Atsumu spanked him again. He whined, lips tight around Atsumu’s knuckles as he forced his fingers deep enough to make Osamu gag. Atsumu held Osamu’s hips still, kept him from humping the floor like a dog. Like a bitch in heat. Yeah, that sounded about right.
Atsumu withdrew his fingers suddenly, and Osamu spat, ridding the salty-bitter taste of them from his mouth, but it was no good. The flavor lingered. He panted, heart racing in anticipation. Atsumu coaxed him up onto his knees, and Osamu went, the fight gone out of him. His head sank below his shoulders and his thighs slipped apart; there wasn’t enough traction on the floor, but it wasn’t like they were going to make it back to bed, not now. Atsumu would fuck him right here and he’d like it. Even the shame made him weak.
Atsumu eased in one knuckle without preamble and sucked his teeth. “You’re so damn tight, how long’s it been? A week? God damn, you’re really something.” If Osamu wasn’t mistaken, it almost sounded like a compliment. The dull ache was familiar, though, no worse than running suicides up the hills outside Inarizaki.
“Just get it the fuck over with,” he spat. Atsumu hit him again for his trouble, this time right on his thigh, and Osamu clenched around the finger. Atsumu whistled like he’d won something.
He added two fingers and began assaulting his insides with quick thrusts, spat on his fingers and pried him open with a third. Osamu’s thighs trembled, but Atsumu held him fast. “You really need it, huh?” he mocked, not a shred of irony in it. “You’re lucky I’m nice and won’t make you beg for my dick.”
“Like hell. You’ve lost your damn mind.”
“You’re dripping,” Atsumu said sweetly, and Osamu glanced down his belly to find that his cock, having sprung free from sweats, was leaking a steady stream of precum on their bedroom floor. He shuddered--disgusting. He’d have to. Later. Something.
He lost his train of thought. Atsumu popped his fingers free and a moment later eased his cock up to Osamu’s twitching hole, the blunt shape of it familiar and yet viscerally too much, Atsumu’s fingers completely inadequate to prepare him, and yet Osamu needed it now so badly that his teeth ached. He arched his back as much as he dared, face burning.
Atsumu scoffed. “You’re sweet,” he said, and this was all the apology he gave before he plunged inside.
He folded himself over Osamu’s back, reached around for his cock the same moment he breached his hole and squeezed just below the tip, holding off Osamu’s orgasm, but his fingers were loose and when Atsumu had slammed home, sinking his teeth into the meat of his twin’s shoulder, Osamu’s entire body spasmed as he ejaculated anyway, spurted white all over the floor and even caught himself on the damn chin.
Atsumu swore softly. “You just--”
“Move!” Osamu gritted his teeth. His fists balled up but he was useless to control his trembling, only at liberty to bark that single order.
Luckily Atsumu wasn’t too cruel to comply, and began thrusting as Osamu shivered through the aftershocks. The spit wasn’t enough and it hurt and Osamu knew he’d be feeling this in practice tomorrow, all damn week actually, but a minute of Atsumu babbling about how tight and cute and fuckin’ hot he was got him hard again, his body quickly adjusting to the fact that that had not been particularly satisfying, or anywhere close to enough.
Atsumu fucked past Osamu’s prostate and Osamu moaned, drooling for it all over the floor. Atsumu jerked him off in time with his thrusts and it was enough to bring tears to Osamu’s eyes, but he didn’t protest, only whined harder and dug his filed-down nails into the floorboards.
“Shit, Samu, you’re so good at taking it, ain’t cha?” He sat up, clutching the nape of Osamu’s neck and smooshing his face into his own drool as Atsumu began pounding his ass harder, chasing his own release. “I’m so fuckin’ lucky, huh? Got a perfect little bitch waiting for me at home.”
I don’t wait for you, Osamu had half a mind to growl, but he only moaned. They’d fight over this shit again later, after Osamu had cum again so hard he’d seen stars. His whole lower half ached, was borderline numb. “S-S--”
“What’s that?”
“Sumu,” he panted. Pleaded.
Atsumu huffed. “Oh, I know what you want.” This time, Osamu had no way of knowing it was coming. Atsumu spanked him hard on the next thrust. Osamu’s body jerked violently, cock jumping and spurting a fresh stream of precum--and again, as Atsumu hit him a second, a third time. He came again on the fourth hit with a broken sob, squeezing down on Atsumu’s cock and winning himself a hissed: “Oh, shit.”
Atsumu’s hips jerked out of rhythm and he groaned lowly as his cock spasmed and flooded Osamu’s insides. He stayed buried to the hilt and ground his hips as if to work his cum deeper as Osamu shivered through his own aftershocks, eyes wide in distant horror at how filthy they were, how filthy he was, how filthy he’d let Atsumu make him.
A minute later, Atsumu pulled out with a wet squelch. Let Osamu collapse onto the floor, into his own cum. He was too drained to care. Atsumu clucked his tongue.
“Look at you,” he said. Osamu blinked lazily and managed a glance back, finding Atsumu flushed, eyes locked on Osamu’s ass. His sore, abused hole twitched as he felt cum began to leak out of it down his ass and thighs; and at once, Atsumu collected his own release on his fingers and began to push it back inside, brow furrowed and lower lip caught between his teeth.
“Fuck ‘re you doing,” Osamu murmured. Atsumu released his lip and grinned, dragging eyes up Osamu’s prone form.
“Just making sure it takes.” He worked his fingers back inside, ignoring Osamu’s whimper of oversensitivity, the wet noises obscene. “Don’t wanna waste what I give you, am I right?”
“You’re insane.”
“If that’s what gets you off.” He dragged his fingers out and wiped them on Osamu’s sweats--gross--and slumped down beside his twin, curling onto his side to face him. Patted his spanked-red bottom like an apology. Osamu stared at Atsumu’s lower lip and felt a surge of need to bite it and kiss it better, sweetly and like they were lovers and not, well. Whatever this was--but he was too spent and lazy to move, so he let his eyes close.
“Shut up.”