Work Text:
Rinne Amagi, by no means, is somebody that Aira loves. Brash, loud, a drinker, a slob. Niki has endless stories about times Rinne has stolen money from his wallet and gambled it away, and Kohaku is clear about how tiring it is to be around an Amagi for so long.
Truly, Aira agrees. Still, he didn't have the heart to tell Kohaku it wasn't Hiiro he was talking about.
Dirty. That's how it feels— a dirty secret that when he dies, will trail behind his corpse like the rancid juice of rotting meat. He's a bag of trash that's split open, a gaping wound and filthy reminder that Aira Shiratori, the heart of Alkaloid, was cheating on the love of his life with his older brother.
There's something exciting about it, a horrible reminder that every time Rinne and Aira sneak off somewhere that this shouldn't be happening. It's a violation of so many principles, because he knows that this isn't just affecting him. He knows that Niki loves Rinne, he sees the soft look he gives him whenever Aira goes down to cafe cinnamon for a parafet. Aira knows it would kill him if he knew what was really going on.
And Hiiro— Hiiro loves Aira so, so much. He sends the kindest texts every morning and every night, always attaching a photo of something new he's learned about the city. Aira finds it endearing, even when he has to pretend he doesn't. Then, he'll put the phone back down and let Rinne shove his cock into him.
Maybe that's the appeal of it. In some sick and twisted way, Aira gets off on the secret of it all. Because it's wrong, it makes the orgasm so much better. One wrong move or a moan too loud and everything they've built is over. In a life where the worst he's had ever done was accidentally walked out of a store and forgotten to pay, now he's a homewrecker.
Rinne taunts Aira with gross, humiliating words that he thinks if Hiiro ever said to him he might just burst into tears, but for some reason when Rinne is the one saying it, all it does is make Aira's cheeks burn and his pants go stiff. It's insufferable, Rinne is insufferable, but his cock is like a cigarette that Aira can't stop smoking.
So, no. He doesn't love Rinne. He loves—
"Fuck!" Aira sucks through his teeth, "Fuck, fuck, fuck—"
"Yeah?" Rinne cackles from behind him with the pitch of a "You like that? Right there?"
He's gotten Aira cornered in an empty equipment room bent over a large speaker that looks more like a seat than something that actually plays music. The worst part is that it isn't even a disused room. A lot of technicians come in here to put things away, and Aira had begged for a different room. Any other room would've been fine! He'd said, but these encounters don't really ever start the way Aira wants them to.
He feels like some kind of hooker, bent over in some dingy back alley that no one bats an eye to because they know the whore's getting something out of it. Except, Aira isn't a whore, but Rinne has done him in an alleyway before, regrettably whilst they were waiting for the tour bus to come and pick them up and their unit mates thought they were going to the bathroom.
"Your ass is always so tight, Ai-chan." Rinne licks into the shell of his ear, wet. Aira winces, trying to lean forward and away, but it presses his cock tighter against the cold metal that just makes Aira gasp instead, "you know you're gonna end up gettin' fucked, but you still don't even try to prepare yourself, do you?"
Aira bites his lip, meaning to punch a hand into Rinne's head, but Rinne holds it down until all he can do is curl his fingers into a fist and scrunch and pull at Rinne's hair. It's untamed but not tangled, though, Aira supposes in this dazed state he's going to ruin that.
"Something tells me you do that on purpose," Rinne pulls out, pausing to bite into the jut of his neck, "Do you? Does Ai-chan like it when I stretch him out with my cock instead of my fingers?"
"Someone could walk in!" Aira sputters, "Rinne—Rinne-Senpa… a-ah!"
He hates that he could probably average the size of an Amagi dick, though Rinne's isn't immeasurably bigger than Hiiro's. They both are big enough for Aira to choke on when he gets on his knees , or when Rinne shoves him down onto whatever grimy floor of whatever shabby excuse of a spot to have sex in he's found for them.
What Aira wants to say is that he doesn't finger himself before these encounters specifically because he doesn't want them to happen, but he's a terrible liar, and he knows Rinne would see straight through it. For a matter of fact, he's probably seen through it since the first time he got Aira alone; because as much as Rinne doesn't like to admit it, he's smarter than he lets on.
He can't help the moan that finally emerges out of every small stifle and gasp that Rinne pumps out of him. It's loud enough that if someone were walking down the hall, they'd know something was up, and if they had their ear pressed against the door they'd know came from Aira.
Rinne's free hand slides down from Aira's hip down to the flesh of his ass, his nails uncut and jagged, the claws of a wild animal cupping the fat there, combing it back and spreading his hole impossibly bigger. The burn makes Aira want to scream his name, consequences be damned, his other hand scrambling for the edge of the carpet in front of him.
"He can't give you this, he can't satisfy you like I do, can he?" Rinne grunts, his thighs clapping against Aira's balls, the friction between skin and gritty metal scratching the front of his legs. "Whenever otoutou-kun fucks you, you're thinkin' of my cock splittin' you open like a fuckin' whore."
"That's not… ngh," Aira pants, "N-not true!"
Every slide of Rinne's cock fattening inside of him, the squeeze of his thighs together with the grinding of Aira's cock into the solid speaker below him makes it impossible for Aira to keep quiet. His moans grow louder, his gasps faster. Whenever he tries to open his mouth to retort against Rinne's taunts, his body lurches forward, the speaker leaning on its feet ever so slightly.
Each wet slap against Aira's ass builds up, the adrenaline surfacing like oil to the top of his body, trails of precum highlighted over as Rinne pumps and pumps through him with enough force to make his stomach ache.
"Gonna churn a baby into you," Rinne huffs, his breath heavy, biting the lobe of Aira's ear. "Won't be able to explain that to my lil' bro, huh?"
It's empty words. After all, Aira can't get pregnant— but the thought of Hiiro finding out about this… taboo, it would all be for nothing.
Aira doesn't want a future with Rinne. He's never thought about soft touches, or spending the night with him actually sleeping in a bed. Things like that were too risky; not when they had people waiting at home for them. Not when they lived in the dorms where people talk.
"Say it," Rinne sucks through his teeth, both hands gripping Aira's waist, thrusting him back and forth making Aira's head feel fuzzy.
"What?" Aira blinks away his tears.
"Who's better," He repeats, his thrusts descending into something shallower. The pull on his insides feels agonising, each rub just barely touching his prostate. "Me, or Hiiro. Say it."
Hiiro loves Aira. He's careful, and gentle, and he always makes sure that nothing ever hurts or feels like too much. Like Aira's made of porcelain, a fine china that he holds with both hands so desperate not to drop.
Aira remembers the first time they'd had sex under the dim lights of the ryoukan in Hokkaido. He'd gotten out of the bath and Hiiro just couldn't stop staring at him, the bite of his lip every time Aira would walk by, lustful and heavy. They couldn't be loud, not with Tatsumi and Mayoi in the next room, but when everyone had gone to bed and Aira couldn't take it anymore, he'd slipped into Hiiro's room and let him have it.
Tender. Soft. It was nice, and Hiiro's kisses were like drinking the sickliest, sweetest, sugar-laid drink in the world. Every time after that was just as good, but there was always an unspoken promise that Hiiro would never take too much. At first, Aira had taken it with grace. After all, it was the start of a new relationship. He was nervous too.
But as he began to grow into the normalcy of it, the pit of not enough began to creep up on him. Nothing was ever hard enough. Fast enough. Even when Aira would ask.
Hiiro makes love to him, but was it so wrong for Aira to want to be properly fucked every once in a while?
It's not fair.
Hiiro wants to marry Aira.
The guilt wallows deeper into Aira's stomach, then flutters down to his cock and evaporates when Rinne gives him a hard slap on the ass.
"Answer me."
"I can't—" Aira sniffs, the sting settling sharply on his skin. "I can't say that."
Rinne clicks his tongue, and bends over again until his nose presses into the shell of Aira's ear.
"You wanna cum?"
He makes it impossible to say no when he angles his hips upwards, ploughing straight into his prostate and completely winding Aira.
"Yes," He hiccups, "Yes! Please."
"Uh-uh, Ai-chan. Please ain't the magic word I'm looking for." He presses forward, grinning from ear to ear. It's the smirk of a predator, and even though Aira's already buried his head into his elbows, desperate, begging himself not to be too loud, Rinne starts up again.
It's relentless this time; the movements of a well programmed machine pressing exactly where Aira likes. The maddening stretch every time he pulls out, the squelch of his wet hole filled with the lube Rinne just carries around with him. Aira is nothing but flushed, head to toe, the blood pounding in his head, his ears, his cock. He needs to come so badly, that if he thinks he doesn't his balls will fall off.
He tries to reach his hand down, anything to get off, to feel like something is being done to his cock, but Rinne's hands catch them easily. They're so much bigger than his, and pin them back in front of him.
"Say it. Who fucks you better, Ai-chan?"
His pride is gone, left in that dingy hallway the first time Rinne had pushed him up against it. There's no coming back from what he's done, so what's a few more disgusting breaches of his dignity?
"You—" Aira babbles, "You do, you do, you do! Hiiro-kun never fucks me like you do! Fuck!"
"That's what I wanna hear," Rinne laughs, cackling in that plastic, trashy way he does on stage. "Come on then. Come on, baby. Come for me."
Aira squeezes his eyes shut, and the permission is the last thing that takes Aira over the edge. His body barely preserves itself, or as much as he can in the situation he's in by shoving the side of his arm between his teeth.
Stars dot his vision, and with a cry he drools into his wrist, the back of his tongue falling limp when the warmth of Rinne's cum fills his insides. It's the most satisfied he's felt all week.
He lets out a sob when Rinne pulls out, the squelch of lube unmissable.
"You okay?" Rinne asks, lightly patting Aira's ass. It's suddenly too much stimulation, so he dazedly swats it away, flopping around so he's properly sitting bare against the speaker. His arm falls to his thighs, on them chewed a pretty mark of his teeth.
He's never okay after these… things that they do. Or well, at first, Aira will feel light and airy like his body is outside of himself. Euphoric or something similar. That is, until he stands up and feels the burn in his thighs and hips. Then, the guilt comes crashing back down in full force and the realisation of what the hell he's just done dawns on him.
Hiiro never makes it hurt afterwards.
Rinne tucks himself back into his pants, the glisten of sweat on his temples. Aira licks his lips, ducking his head.
"I'm fine," He says, his voice hoarse. "I think you should go."
Rinne regards him for a moment, a silent scrutiny that looks sharper and less wild than the one he's used to. It's the look that Hiiro used to give him before they were dating— curious but unsure of how to approach him. He guesses both of them never want to push too far when people's feelings are involved, which is a pretty fucking ironic thing considering what they're doing.
What is he even saying? No, Rinne could never be worried about Aira.
Rinne bites the inside of his cheek, his shoulders falling. Seemingly, he's made his decision.
"Welp, can't help ya' if you don't want it." He grins, walking towards the door. When Aira turns to start fixing his pants, Rinne stops, his hand stuck on the handle. "Ya' sure you don't even want a water?"
"No! Just get out!" Aira shouts, his cheeks flushing.
"Jeez, fine." Rinne clicks his tongue, finally pulling the door open. In a bold show of audacity, he looks back at Aira one last time.
"I'd say see you never but… we both know that's not happenin'."
The door clicks shut, Rinne's cackling fading out. Aira thinks he stays in there for about another fifteen minutes before trying to get to the door himself, a light hobble in his step and Rinne's cum dripping out of his ass.
He's right. For as long as Rinne is around, Aira will keep coming back for this cycle of— of sex and guilt again, and again, and again.
I'm sorry, Hiiro-kun. He mutters to himself in one last prayer. But I just don't think I can stop no matter how much you love me.