There is a game Seimei enjoys very much; shhh, you mustn’t tell Ritsuka. It’d be game over if Ritsuka found out, and Seimei hates losing.
The rules are very simple: when Ritsuka is asleep, do not wake him.
Seimei is very good at this game. It’s only natural, of course, because Seimei is very good at everything. He’s started challenging himself: the game is easiest when Ritsuka falls asleep curled in his lap (because it happens so often; he is beloved and safe haven for his poor little brother, and Ritsuka will go to him more than either of their parents for comfort), already cuddled close in the half-circle of Seimei’s arm. That’s easy, though, too easy, and so Seimei makes variations: come into Ritsuka’s room after Ritsuka is asleep, pet Ritsuka as he dozes off, let his fingers skim under his cute little brother’s loose pyjamas and over the sharp angles of those skinny hips.
He can mouth Ritsuka’s feline ear, holding the tip delicately between his teeth, and when it twitches and Ritsuka makes sleepy waking noises, he retreats. He spreads his fingers wide over Ritsuka’s chest, so skinny he can almost span it with that single hand, and his pinky presses alongside a tiny pink nipple, stroking until Ritsuka’s nose scrunches up and a noise rises from deep in his throat. Each time Seimei retreats, stroking his hand in slow steady motions down Ritsuka’s side until his brother calms and his face smoothes back into deep sleep.
This has become his favorite game now, especially as Ritsuka begins to spend more time with him, retreating to Seimei’s room more often than his own. He pushes the rules a little further every time, his lips to Ritsuka’s little white throat and his hand fisting the length of a skinny black tail. The only rule is that Ritsuka can’t wake up, even briefly, though there is a bonus if he arches and makes throaty noises that might, in wakefulness, be his brother’s name.
Seimei hasn’t lost once.