When you take a dump and the backsplash hits your testicles.

During the act of rough oral or deep throat, it is when the man receiving is suprised with a spash of self gratitude when the female regergitates on his member. {This can also happen when the splasher is either ill or highly intoxicated, which makes it that much better.}

Basically, your balls are so sweaty and smelly that you have no choice but to wash them to keep any remnants of dignity. Thing is, your only option is the sink in the public restroom. So you drop those shorts, flop your boys in, and proceed to splash them in a Jamaican-style fashion.