Always happens in a awkward moment, ie, standing in a queue, in a important meeting, chatting to people. When you pants have ridden up your bottom crack, that you feel like screaming.
''I would love to stay and chat with you but i have a slight P.U.M.A problem to deal with first''
Roommate 1: Hey, did you buy some Arizona from the P.U.M.P. yesterday?
Roommate 2: Yeah, why?
Roommate 1: Because it's already gone...
Roommate 2: Damn it, well I guess it's your turn to go to the PUMP and get some!