When you shove your cock so far down your gf's throat that it pushes her organs out her ass. You can make bets on what comes out first, hence the "roulette"
When Sarah didn't make enough sandwiches, Joey decided to play some Ohio Organ Roulette with her.
When you fail at something in life (eg. failing an exam or not getting a job), go home and spend an hour just standing in the shower, propping yourself up against the wall with your eyes on your feet.
Caleb knew the only thing to do after he didnt get prefect was take a failureshower.