I think the more you hang around and associate with a sex, the easier it is to be more relaxed in a social, and possibly sexual way with either sex... i notice that when i had a girlfriend, i was much more social with girls and they were easier to talk to... but then i was single, hung around with all my guy friends, and i suddenly didnt care about trying to get girls.. it wasnt a sexual thing, just social, but it was a difference i could note.