
This is one of the tropes that the uke/seme treats the mc like a brother and the mf mc see him in romantic way like why would you see it like that...it feels like you're having a crush on your brother like eww and the supposedly "brother" will get weak 'cause the sex is good and that "brother" have a brain and smart...
The white haired guy from start is kinda like Hans not the looks but the intention and personality fits.