Heh, I don't think for a second oral sex consists of a loss of virginity, but others have different views. For that matter, I technically don't even consider having anal sex with a chick losing your virginity. For loose interpretation, the only way I would consider a sexual act an act of losing your virginity would be if there is the possibility of getting a female pregnant, without any outside tampering.
Yes, I know artificial insemination wouldn't consist of losing your virginity, which is what I meant from "without any outside tampering". Male's penis thrusting in a woman's vagina is a loss of virignity in my book.