A person who refuses to recoginize their heterosexuality
That man is a closet heterosexual
A straight man/woman who pretends to be gay with the hope of sleeping with a member of the opposite sex, playing on the possible fantasy of "converting" them.
Girl: How do you know you don't like women if you've never slept with one?
"Gay" Guy: I don't know. I never really thought about it.
Girl: We should totally fuck.
"Gay" Guy: Well... I guess I could *try* it, sure. ;)
*30 minutes later*...
"Gay" Guy: Yeah so, I'm actually a closet heterosexual and just wanted to get in your pants.