I don't remember much about this one, I know it's yaoi or shounen-ai though haha.
I recall a scene where the uke, a high school student, is talking to his girlfriend (he was breaking up with her and admitting he loves the seme). The seme is (probably) not a student.
edit: I remembered something new. I believe there was another boy in uke's class (he liked uke's girlfriend if I'm not mistaken). At first they didn't get along, but later when the guy found out that the person uke likes was a guy he told him that he liked a guy before too. They talked about it too. It's rather vague but hope it helps (it might also not be from the right manga..haha..sorry)