Responses
The MC actually loves the hyung (refer to chapter 2) but decided to push him since the hyungs father discovered their relationship (refer to chapter 16) without telling the hyung the reason. I think the hyung became obsessive because of the MC's action.
YESSS, TAKE ALL THEM FINGERS (๑•ㅂ•)و✧ (But I'm really hoping the main couple ends up happy. And that the fact he can calm down with the seme means it'll eventually translate to real feelings.)