Okay Young lady,
I say that because I'm a 40 year diva woman 'smiles', been there done that.
My 'Q' to you is,
"Who initiated the bet, you or him? Reason being, not to make you insecure as I hope your relationship is with your boyfriend is secure. You are concerned because you want to be intimate with him like your used too before leaving but is he concerned about it too? If not maybe he's confident about winning because he's going to or is getting it from somewere else? Hum??? Could be wrong but don't waste your time on meaningless wagers! Have sex BUT be CAREFUL! Protect yourself always and don't take forgranted that you are the only one. You are sooo young, your still a baby!
Take care,
Robbie