I know almost everyone has this hc in which Dazai leaves and Chūya is devastated, but, what if not? // somehow this become a sex&Chūya!hc
Chūya’s 18, almost his whole life in the Port Mafia, definitely all his memories under Kōyō’s wings, and what is the most important lesson she has teached him?
never fall in love with a mafioso - it never ends well.
And Chūya has seen it, too: none of the girls who works at Kōyō’s brothel and engage with mafia customers get the happy ending. Their are always left behind, in the best cases (the men decide they’re not really worth it). Usually, their partners get killed, because this is the Mafia after all, and death is always waiting around the corner. In the worst scenarios, the girls get killed, too, and soon enough it is as if they’d never existed.
So, since the begging, Chūya knows better than to fall in love. It just, it is not worth it.
Sex, on he other hand —it is.
Chūya’s a fucker, in the literal sense of the word. The looks accompany him, and with that, everything’s easy. He was having sex even before than Dazai’s was even interested, though he’s never shared with his partner that kind of information (they both know that the moment Dazai knows who Chūya’s first was, that person is dead).
He enjoys everything about sex, and it is a good thing, because sometimes he uses to his advantages during missions. Gravity can help you break unbreakable doors, but with a wink in the right time you don’t even need to use it —the target himself opens the doors for you (He doesn’t tell Dazai about those, either. He did once, ad it didn’t end well for anybody).
Sex with Dazai comes first a while before soukoku is created. Dazai’s not a womanizer for nothing, and Chūya enjoys every moment of it. But that’s just what is —an enjoyment, a pastime. They keep doing it for some years, and if during that time Dazai develops feelings (his thrusts are more tender, his kisses more intimate), Chūya does not notice, or cares.
This isn’t to say that Chūya does not care when Dazai leaves: he’s his partner, of course he cares. He disappears leaving behind no notes, no explanations, and Chūya’s really angry.
It just —he’s not heartbroken. Since the beginning, he knew better than to expect a happy ending.