Work Text:
Kunikida didn’t quite understand his feelings right now. He didn’t know what he wanted.
The way that Dazai was fucking Atsushi was powerful, snapping thrusts that seemed to twist Atsushi up from the inside and smooth him out all over again. Dazai was tall too, holding Atsushi up as if it was nothing, as if the boy (teenager, really) weighed nothing, pinned high up against the wall and pleading for it.
“Dazai-san,” Atsushi rasped quietly, as if he had no air, “I can’t, I can’t-” can’t handle it? Can’t hold his orgasm off? Can’t breathe?
That’s what Kunikida felt like, like he’d walked into an alternate dimension that made Atsushi into this lithe, soft creature of wetness and sound and Dazai into a hard wall of skin and scars, shining pale in the moonlight. Hell, they weren’t even in the privacy of their room, Kunikida knew for certain that The Agency’s apartments were several buildings away to the left, what made the two drop drawers in the quiet Yokohama alleyways and, and, and fuck like animals?!
Even thinking the word fuck made Kunikida blush and squirm, shocked to find himself breathing heavier and riveted by the sight.
A strangled gasp made Kunikida blink through his daze, Dazai had thrown his head back and shuffled Atsushi lower, and so the boy seemed to hang there between solid muscle and brick wall, legs spread obscenely wide. His thrusts were hitting deeper, pulling beautiful noises out of the boy and clearly getting to Dazai, because his back was flexing and glistened in the blue light. Sunset eyes were hazy, looking into the shadows where Kunikida was hidden, and the detective thanked every lucky star that Atsushi hadn’t seen him. Kunikida couldn’t see where the two were connected, but he could hear it.
Every flex of Dazai’s back, thrust of his ass, half hidden by the detective’s sloppily shoved down pants, and a slick thud seemed to resonate in Kunikida’s gut. He half thought he imagined it, that meaty grind into a warm hole, a tight hole, by the way Dazai was growling now, low vibrating growls that sounded in perfect counter point to Atsushi’s half slurred begs. They were fucking so hard, and it was a wonder to see Dazai’s strength, holding Atsushi there and still filling him so good.
“Oh my god, please, I’m going to, right there, right-- There, Dazai-sa—“ silenced suddenly by a bandaged hand, since the brat was getting loud, Atsushi started flailing a bit, his arms scrambling to hold onto something. He was going to cum.
Kunikida was shamed by the hardness in his pants, but holy, holy fuck, this was hot and heavy, and Kunikida had never had sexual relations like it. A hand wavered, travelling to his crotch without bidding and the first brush of fingers made him bite his lip, eyes glued to the scene. He was a slow lover, a gentle one, and he wondered, darkly, hidden in the shadows and not feeling like himself, if Atsushi would scream into his hand like that, or if the brat would tremble that way if Kunikida was the one who had his chest presses against Atsushi like that. Maybe he was jealous of the way that Dazai fucked his colleague, his eight-teen year old colleague like it was his last day on earth, like Atsushi was there just for him, like with every thrust of his cock he took more and more of the were-tiger for himself.
Before he could slip away unnoticed, honestly, it was a shock that Dazai hadn’t noticed him yet but Kunikida figured he wouldn’t pay attention to anything except the way Atsushi was coming around his cock, milking him like that, Kunikida realized that the haze in Atsushi’s eyes was growing incredulous, confused, with realization filtering in.
But even Atsushi couldn’t deny the power of his own orgasm, Kunikida felt blown back by the boys wail even though Dazai had a large hand across his mouth, practically suffocating him. Atsushi jackknifed, clawing at Dazai, shaking and drawing Dazai’s orgasm alongside his own. Kunikida noted, somewhat numb but overly sensitive – his fingertips on his cock were frozen because he was sure if he moved he’d come right then and there .
Dazai bit down when he came, moaning through soft flesh his release, coming so much that it gushed when he kept thrusting, falling to the dirty alleyway floor.
“K-Kunikida-san?” Atsushi gasped with his first breath after orgasm, still twitching and trembling around Dazai, clenching fists into Dazai’s hair. His mouth was wet, red, and tempting, and his voice,breathing around ecstasy like that, Kunikida would never forget.
Kunikida walked away very quickly before he could be identified by the suicidal-maniac as a voyeur, hoping futilely that Atsushi would forget it forget it please, because he never would. Fifteen minutes later Kunikida banged into his empty home, locked his door and fell to his knees, his cock already out and weeping. He thrust up into his hand, sucking in air through his teeth and coming right there at his front door, wishing desperately that he could be the kind of man to fuck to fuck Atsushi like that in an alleyway.