That would be because there is really no such thing as a "bi-sexual." I once read that psychologists agree that given a sexual choice these "bi-sexuals" will ALWAYS choose a member of their own sex.
Saying they're bi-sexual is just a defense mechanism to make themselves feel comfortable about their depravity, in the opinion of the OldPossum.
I agree with you. And in my world, you don’t just try gay. A man who has done anything sexual with another man, even once, is a gay.