I know that BL Manga's tend to be more idealistic than realistic, but this actually does a good job of representing what might happen when someone who is not sexually attracted to men gets into a relationship with his best friend.
Most BL Manga's show 'straight' guys enthusiastically becoming uke's, often after being raped and I have a problem with that. The usual way of getting round that is to make the uke an idiot and the seme a manipulator, this as common as manly top and girly bottom combination
