Pleasuring ones self shamelessly in the bathroom at your place of employment. If you’re good enough to blow your load in a stall you’re not Crumpin Off. This act of self degradation is exclusively preformed at a urinal for the world to see.
“Dude did you hear was Dean jackin the beanstalk in the bathroom?”
“Yeah man, he was beatin that dick like it owed him money. Dude was straight Crumpin Off!”