Work Text:
They don't know when or how it started.
Maybe it was because Osamu would let his arm brush against Astumu for longer than necessary, fingers nearly intertwining, and Atsumu wouldn't pull away. Maybe it was because Atsumu would still sneak into the bottom bunk to cuddle Osamu, and Osamu wouldn't stop him. Maybe it was the night they had a physical altercation, Atsumu pinned under Osamu when they kissed for the first time. Atsumu would say Osamu leaned in first, while Osamu would say Atsumu grabbed his shirt pulling him in.
Whatever the case, the twins are a lot closer than normal siblings—and they like it that way.
"Oi, 'Tsumu."
Atsumu doesn't look up from his place by the sink, hands elbow-deep in hot, soapy water, but grunts in acknowledgment. A welcoming warmth overtakes him, familiar arms wrapping tight around his waist, a chin settles perfectly into the crook of his neck. Even if nothing had been said, he'd know it was Osamu.
"Forget about yer chores 'n come to bed with me?" Osamu asks, giving Atsumu a light squeeze.
"Ya know I can't do that, 'Samu. I already got in trouble for havin' skipped 'em yesterday," Atsumu says, "'Sides, ma will probably be home soon."
Osamu luls his head from side to side. "But she's not home yet," He hums, breath hot against his brother's ear, "and I've missed ya."
"We live together, idiot. Ya don't have time to miss me," Atsumu scoffs.
"We live together and yet I still miss ya..."
Atsumu flicks his gaze upwards at that, making eye contact with his twin in the darkening kitchen window. Osamu, with his gray hair and handsome features, identical to Atsumu's own and yet uniquely foreign in the minor differences. Osamu nuzzles his nose against the side of Atsumu's face.
"Shut up," Atsumu says, failing to hold back the smile creeping up on the corners of his mouth, "How long have ya been waitin' to use that line, huh? Loser."
Osamu offers a lazy smirk but doesn't respond, instead sticking his tongue out to lick a strip up Atsumu's neck, not once breaking eye contact. His saliva is cool and makes Atsumu's skin tingle as it drys. An inconvenient feeling works its way downwards and Atsumu does his best to ignore it, lifting a hand from the water to half-heatedly swat his brother away.
"Don't even think about it, 'Samu."
"Don't? That's no fun..." Osamu hums against his skin, "Please? I've been thinkin' about it all day."
Atsumu flicks Osamu's forehead with a soaked finger. "Ya shoulda asked an hour ago then, ya scrub. Ya hav'ta wait till ma goes to sleep."
Osamu grumbles and Atsumu takes it as a sign of him admiting defeat, managing to get through a few more dishes in peace. Things appear to be going well until he gets to the cutlery—the part he always saves for last—where Osamu makes a move. One hand travels up Atsumu's shirt, while the other travels down, playing with the hem of Atsumu's sweatpants. Atsumu can feel his cheeks burning—a mix of irrtation and arousal. He knows Osamu's eyes are still locked on his reflection in the window, watching him with interest. When there are only a handful of spoons left sitting at the bottom of the sink Atsumu lets out a sigh of relief. It turns out Osamu can be a good little brother, he thinks to himself—right before Osamu bites down just hard enough on Atsumu's neck to make him flinch.
"Samu, what the—Ya little shit! M' serious, quit it. If ma comes home and—ah-" Atsumu's words catch in his throat, as Osamu's fingers begin working a nipple, twisting and pinching the bud. "Ya fuckin'... brat..."
"Don't wanna wait any longer," Osamu says. His mouth works its way along Atsumu's neck and down a shoulder, sucking on the skin, leaving pretty purple marks in his wake—although he places them carefully, only where the twins themselves would see.
Atsumu bites his lip, arousal pooling low in his abdomen, and he hates himself for it. Hates how much his body reacts. Hates how much he loves it—how much he loves his brother. Osamu fondles Atsumu's right nipple until it's hard, then swaps to the other, his lower hand migrating south, mere centimeters below the hem, just enough to brush pubic hair. Atsumu's whole body twitches at the sensation and a low, traitorous moan escapes his throat.
"Heh, 'Tsumu, the sounds ya make for me..." Osamu coos. He continues his teasing, slow and methodical, the way he knows from practice makes Atsumu's stomach flip. Long, slender fingers are now tantalizingly, dangerously close to Atsumu's cock.
"Shut... shut up..." Astumu manages, praying it sounds less like a whine to Osamu than it does to himself, "Stop it. We're gonna... get caught out here 'n then what'll we—mphf—"
A hand whips upward to cover Atsumu's mouth, going straight through the neck hole to get there.
"Listen, ya got three seconds. Push me away and I'll leave ya alone. Promise."
Atsumu fidgets. They've never played this game outside of their bedroom.
"Three."
He swallows. It'd be dangerous.
"Two."
He shuts his eyes. They'll be vunerable to getting caught.
"One..."
Yet the thought is as intoxicating as it is frightening.
Just like that, the hand in Atsumu's sweats dives the rest of the way, fingers wrapping themselves around his half-hard cock. Osamu thumbs at the tip, rubbing precum between his fingers, before then settling into slow, rough strokes from base to head, eliciting another sugary moan from Atsumu's lips. Atsumu's legs tremble, causing him to nearly fall face first into the sink. He grips the counter to keep his balance as Osamu ruts against his ass in time with his strokes. Atsumu steadiest himself, rolling his hips to create more friction, fucking into Osamu's hand. He can feel Osamu's own hardness forming as he does so. Osamu nips at Atsumu's already bruised neck again, but he's too forceful this time—he breaks skin and Atsumu jerks at the sudden pain.
"Turn around," Osamu growls, his voice no longer teasing, but low and thick with hunger. He removes his hands to coax his brother to face him and Atsumu whines at the loss, even if it's only for a moment. The second Osamu can see his twin's face properly he crashes their lips together. It's a hard kiss, long and wet and sloppy. Atsumu's tongue fights for dominance but Osamu overtakes him with ease.
"Fuck, 'Tsumu... need ya so bad tonight," Osamu murmurs into his twins mouth. He pulls his shorts down, using one hand to grasp both of their dicks, pumping them at once. The other finds its way to his brother's waist, pulling him closer. In turn Atsumu's hands travel to tangle in Osamu's hair. He gets Osamu's bottom lip caught between his teeth and tugs. The heat of their cocks being fucked together is almost unbearable, but it feels so damn good. Too good. Osamu's pumps begin to lose their rhythm, both brothers edging close to release.
"'Sa... Samu... are ya gonna... ’m gonna... hah..."
"It's okay... 'm close."
Osamu sucks hard on the skin over Atsumu's pulse point. It's too high, too risky, he shouldn't do it—but in the haze, it feels right. Atsumu doesn't make any real attempt to stop him either, settling instead for pulling a little harder on his hair, which lifts his brother's face slightly, although it only serves to make Osamu bite at Atsumu's earlobe with full teeth.
"Ah... ah... 'Samu-... fuck!"
"'Tsumu... ngh—"
They cum at the same time, spend mixing together and spilling over Osamu's hand. Atsumu slumps against his brother, panting and they take a few moments to collect themselves.
Then they hear it. The soft click sound of a key.
"Atsumu! Osamu! I'm home."
Ma.
The twins stare at each other for a moment, in horrified silence. Bottoms down, Osamu's hand dripping and sticky, covered in cum. Atsumu, hair stuck to his forehead, slick with sweat, neck, lips and ear bruised and red. There's no time to run and no time hide.
"Fuck. Fuck, fuck!" Osamu hisses under his breath. He pulls his shorts up and pushes a frozen Atsumu off, spinning him back around to face the sink. "Cover yerself up and don't move."
Atsumu doesn't say anything, but he does obey, adjusting his sweats and tieing the string so tight it hurts. Osamu winces as he sticks his hand in the now cold dishwater, to wash the cum from his fingers. He spares a quick apologetic look over to his twin. Atsumu's face is flushed a deep pink, a mix of 'still horny' and 'I hope I turn into a speck of dust and disappear' spread clear across it. Osamu snatches up a dishcloth and throws it around Atsumu's neck. It's all he can do, as he settles down into the nearest dining chair and their mother waltzes into the room.
If she suspects anything her face doesn't show it.
"Hello boys, everythin' go okay while I was out?" she asks, placing a bag of groceries on the table.
"Yeah, we're fine ma, ya weren't gone for that long," Osamu says face resting in his clean hand. He can't hear much over the sound of his heart hammering in his ears, but he silently prays his voice sounds calm and nonchalant. "'Tsumu didn't flood the house or nothin'."
He watches Atsumu in his peripheral vision, who remains absolutely stiff. Osamu clears his throat.
"Hey, uh, 'Tsumu and I can put away the shoppin', if ya want."
"Are ya boys sure?"
"Course. We don't mind at all," Atsumu pipes in, turning only slightly, face all smiles, and a hand expertly maneuvering the towel situated around his neck. Not his first time hiding fresh battle scars, but certainly the first time being so close to annihilation.
"Oh, Atsumu, are ya alright?" their mother asks with concern, "Ya look feverish."
"Ah, just wet. 'Samu wouldn't leave me alone to do the dishes, so I got some water on us both." Atsumu says, luckily not missing a beat. He shoots Osamu a dirty look for good measure. It helps sell the point of them roughing around, but Osamu can tell Atsumu wants it to sting. Just a little.
After a few seconds, their mother laughs. It's warm and bright, and it fills the boys with guilt. But never quite enough of it. She plants a kiss on the side of Atsumu's head.
"Alright, well don't be too long, you'll catch cold if ya stay like that. I love ya's."
"Love ya too."
Once she's gone, the twins let out a collective sigh of relief. Osamu helps Atsumu finish the last of his chores and they make sure to wash the sink out with bleach and vinegar. When they finally make it to the safety of their shared bedroom Atsumu jabs Osamu in the side with his elbow.
"That was way too fuckin' close, 'Samu. Ya fuckin' bastard, ya know yer a real piece of--"
He's tangent is quickly cut off, Osamu cupping his face in his hands and kissing him. It's a gentle kiss this time. Apologetic, but still yearning. Their lips are slightly chapped from earlier, but Atsumu doesn't mind in the least.
"I know ‘Tsumu. M'm sorry."
Atsumu's tension releases as he leans into the kiss, allowing Osamu to slowly push him backward until they're falling into each other on the bottom bunk. Osamu breaks their kiss, hoisting himself up on an elbow and pulling Atsumu close against his chest.
"But," he starts, fingers running circles on his twin's back, "It was pretty fuckin' hot, right? I mean, god... yer reflection in the window... Fuck, 'Tsumu m'a dream about that face."
"Shut up, idiot. So full of yerself yer gonna dream of yer own damn face."
"Oh please. That slutty face ya make is nothin' like mine."
"Tch. Whatever... yer the one who made me look that way."
"Oh, I know, and m'a do it again."
Atsumu is too tired to fight him on it, grumbling under his breath something that sounds suspiciously like, "Yer stupid, but yeah, okay. It was fuckin' hot."