Searching the title for this weird thingy

Uhhh so there was this reeeally messed up yaoi I read a while ago and it’s stuck in my head soooo... It was about step-brothers I think and the little brother got obsessed with the big bro after some time and apparently the little bro had a plastic surgery to look exactly like his big bro and when he’s having sex he watches his own face from the mirror or sth while imagining he’s doing his big bro (yeah I said it was really messed up) Oh and I think the big bro was kinda disgusted by him or sth because of how he became??