Either when a single person holds in multiple farts and one time, and decides to release. Or when multiple people hold in a fart and release.
"Man, it smells like shit
when you fart pool, go one at a time from now on."
"Okay, Seriously guys, who farted? If all of you guys are fart pooling, get the fuck out!"
When you think you've lost one of your testis, and you start to freak out. You would call the CIA, FBI, and the SWATS to find that missing testicle.
"OH SHIT! Ball Gone MIA, I repeat, Ball Gone MIA! Call in the Bomb Squad!"