Well if they both agreed to do so, I don't see anything wrong with that. I think it's an obsolete way of thinking that everyone waits till they get married, because they don't. People are getting married when they are older compared to in the past people would get married at 15 and whatnot and now it's closer to 30. Also, there is nothing wrong in being sexually active if you are safe. If they both consented to it then there's nothing wrong with it. You don't need love or a relationship to have sex with them you know? Anyway, you shouldn't judge people let them do as they want with their virginities and whatnot, and just worry about yourself.