I think that true attraction would be pretty obvious to notice. Otherwise, there aren't really any reliable signs, from what I've read. More people seem to be bi-curious than actually bisexual. It probably has to do with the difference between emotional attraction (which would be considered bisexual) and physical attraction (which could be bisexual or bi-curious behavior).
The only way to know for sure is to talk with the guy. Chances are good that if he is bi-something, he won't tell you the truth for a long time. There's almost as much stigma attached with being bisexual as being gay (or even more, in the case of men).
Being bi as my as my old roommate and good friend used to say. Bi is just being able to have a deep emotional and sexual relationship with either sex. He is the only bi man I have known (also worth noting he was totally unwilling to have open relationships).
Honestly if he is attracted to men you do the same thing as a man who is attracted to women. You fight for him or leave him.
Well I have say that I have concluded that I must be bisexual. I don't know to what degree. I have never been with a guy in any real heavy sexual act. I love watching bisexual porn (limited gay porn) and lesbian porn. I almost never look at straight porn. I would rather masturbate in front of the hotest woman than have sex with her. Why, because I want her to watch me enjoy playing with my own penis. I love some of the girls I have dated. They enjoy doing bi things to me as well.
Honestly I wouldn't even care because if he was BI I would respect his decision and be like you do what you have to do. Because that's your decision I wouldn't treat them differently because everyone deserves to be treated equally. If you think he is BI be like I have a question I don't mean to be rude but are you BI?
I've been in a relationship with my child father for three years. Before he met me he was incarcerated years earlier. I'm curious if he is bisexual. I asked he always gets annoyed and denies it. He said he can never do anything with any man cause it would cause him to question his whole life. He said he wouldn't mind being friends with gay people long as they don't try nothing sexual. I'm curious why he likes to suck my fingers and Roughly have annual sex. Does he display signs of bisexuality.