Blow Job Lottery
When a guy hopes that by doing the right things (sex acts or otherwise) for a girl, he can get a blow job. This can result in either winning (getting a blow job) or losing (not getting a blow job).
Guy #1: I was totally messing around with this chick last night and I won the Blow Job Lottery!
Guy #2: Drinks for everybody!
Guy #2: Drinks for everybody!