1. When someone poops on your chest and doesn't have the common courtesy to either a. have poopy sex with you, or b. let you do it back.
2. When you think that you need to shit really, really, really bad. Like you're going to created the biggest turd log in the history of the world and it turns out to be a fart or more dissapointingly a nugget.
3. When you are going out to a bar, club, concert, party, whatever and think it's gonna be a blasty blast but it turns out to suck.