Looking for a Yaoi Manga

I read this one a while back and thought it was really good, but now I can't find it. I think it was a spin-off of another manga that was about a student and a teacher, and this one was about the uke from the other story's friend. The friend had like a weird relationship with his older bro after seeing him having sex with another man. He totally wanted to smash, but didn't wanna break up the family or make things awkward, so he went away for school. He ended up living with just his bro after and the sexual tension was mhmmm. Its also possible that they weren't blood related brothers, but I'm not sure.