MANHWA HELP!!

Hi guys I’ve been trying to remember a bl I read (ever since I lost all my readings lists..)

Anyways I totally forgot the name but leads have black hair, one of them is like gangster mafia (a)? And he takes in this guy(b)initially thinking he is a girl and b gets motivated to like go school more

In one of the chapters b sees a having sex with someone else and gets jealous

If I remember correctly, a also has been looking after b’s mum, and they go to see b’s mum and she’s looking a little sick even though she says she’s recovering I think th house was wooden and big with a garden? Like traditional Korean house.

Anyways please lmk if you know what I’m talking about