His brother is a strange, strange creature.
Kouha supposes he has no room to talk. He likes to hurt things, likes to watch people squirm, likes watching the reactions play across their faces after they've begged for him to do things that will hurt—that moment they all have when they wonder if this is what they really, honestly did want, and then the blissful afterglow when they realize that yes, it really is, please do it more.
Koumei is like that, but all the time.
He wonders why his brother tries to hide these things, really. Koumei is a subtle creature by nature, but to Kouha, everything about him is obvious. It's why it comes as no surprise to simply walk in on the sight of his brother flat on his back, held down by strong arms and yanked down onto the big, leaking cock of one of his guards, all as another shoves its way into his mouth after his lips are pried apart by insistent, groping fingers. Kouha doesn't make a sound—instead choosing to watch silently after sliding the door shut, his own breath a quick, fast thing as he watches Koumei gag and choke, hungrily sucking and playing up the struggle all the same, until the guard in his mouth simply slings a leg over his chest with a grunt, and fucks his mouth that way, holding his head to the floor and taking him with short, ragged jerks of his hips.
Even if Kouha can't see it, he hears his brother cough, hears him sputter as the man undoubtedly comes over his face. Kouha bets his brother likes it, the whore. Koumei has never done anything but hide behind a facade of bookishness, preferring a quiet study to a battlefield any day, with the only violence he enjoys being the kind that is taken out upon him.
Small wonder, that he throws himself at his own guards' feet, begging to be taken and abused like some dime-an-hour harlot.
Kouha waits until the other guard finishes, filling Koumei's ass with a ragged sigh, and he hears Koumei whimper, squirming against their hold. His own cock swells and Kouha shifts, thinking hardly of that, and more of how his brother looks, splayed over the floor and mussed and abused, and he gives a little, amused snort at the pitiful protest he puts up when another man moves to mount him like a dog.
That's when Koumei notices him.
The flush on his brother's cheeks is all the hotter, and the guards freeze, as if they're going to be punished. Kouha merely smiles, waves a dismissive hand, and leans back into the door. "Go on," he says, voice high and breathy. "Keep going, he likes it."
He wants to tell them how to fuck Koumei so he'll like it even more. Is it even necessary, though, when Koumei's own cock is that much obviously harder at knowing Kouha is merely watching? The next guard's cock is big, too, and Koumei cries out when he shoves in too fast, too deep, his thighs trembling and splaying wider as he's fucked, and Kouha swallows, thinking never mind, they've done this before, they know what Mei likes.
By the time Koumei comes, spilling hot and messy over his own stomach, used by a good few more men, Kouha can't stand it. He has to step forward, to swipe delicate fingers through the splatter over Koumei's skin, has to push them against Koumei's lips for him to suck clean as obediently as any whore. The gaze that looks up at Kouha is hazy and delirious and altogether adoring, and Kouha twists his fingers against his brother's tongue, strokes his own cock that much faster, and shudders, hard and relieved, as he scoots forward to spill over Koumei's face at the last moment, marking him with his own claim that he knows is a much, much more permanent thing.
He supposes, in many ways, he's just as strange as Koumei—or perhaps that's an understatement, when he enjoys this all so very much.