Damn, B, the less fortunate of the three. Well, putting aside not trying to form a relationship with them like I advised(which I'm guessing is hard for you to do because of your feelings or whatever), how does this person even feel about you? You said he was a manslut, is it to the extent that he would never want an asexual relationship at all? You're obviously attracted to his personality, are you willing to cope with a full on gay relationship? It is possible, but I doubt this is that serious. Although you did use the word "love".

Anyways, you could always just not be in a relationship with them, and stay good friends like I said before. Friendships are important too.