I don't think they are practicing homosexuals, in fact recent stats suggest there are fewer homosexuals and lesbians than previously thought,it was basically propoganda brought out by the Gay rights lobby,although numbers of greedy bisexuals are accurate.
My guess is, that men are very competitive,you describe yourself as a prettyboy,they are comparing themselves to you. Goes back to cavemen times. Girls do similar, I remember looking at this very pretty girl in tescos once and this other girl noticed me looking, and I noticed her glancing at this girl many times afterwards, sizing her up.