a need help to find this Bl manga

so there are three characters in this story guy a guy b and guy c
guy a is the teacher of guy b and c
and it seemed like guy b fell for guy a so they started going out
but after awhile the whole school found out about it
and it seems like guy b is the only one who minds about it
so he keeps getting nausatic or keeps sweating whenever someone stares at him
but even after that guy a and guy b still continues their reltionship
but it wasnt exactly love
its like guy a was only using guy b for his satisfaction
guy b thougth of that and is scared that guy a migth leave him for good
this is where guy c comes in
guy c started hanging out with guy b for no reason
guy c is a very cheerful guy and is very concerened for guy b
he feels bad for him but just because guy c thougth of guy b as pitiable
isnt the main reason why guy c cares for guy b
i think he was starting to develop feelings or just really worried
so after sometime
during class guy a was like trying to embaress guy b infront of everyone
nobody knows that guy a was hte partner of guy b
so this made guy b very sad that even his own "lover"
is kind of slut shaming him or gay shaming
so guy b went to the clinic and guy a follows him
and they started doing sex there after that sex
guy a and c met and c confronted a about b
and guy a admitted that he was only using guy b for sex
this made guy c really angry
so guy c told guy b what guy a is really doing to him
but in the end guy b just bitched around and still protected guy a
and there was this scene where guy a said to guy c that
"maybe if you take his place ill stop doing that to him"
at the end
guy a and c
ended up together