The only way to know is to ask him.
Guy: Hi!You: i'm gay.
Kiss him.
Girls can tell or know if a guy is gay by observing his behavior in a group of men.
There's no better way to find out than ask the guy if he's gay. That way you will know and can move on if he is gay.
you ask him
Just ask
proof it baby proof it!!
ummm ask him?
You know that your gay when you kiss a man have any sexual relationship or really like a guy. im gay & im proud of it.
he asks him out ^_^
If he prances about gayly and watches gay porn!
Although not common it has happened that a straight guy who gets to know a gay guy can fall in love, but the percentages are very low.