also known as "PF", the condition where a male's
penis- whether donning underwear or not- is unknowingly, or knowingly showing through his
pants and consistently hitting said
pants as he walks, runs or generally moves. Females tend to whisper "PF" to tell one another that they've spotted penis flop on a male.
"Check it out,
girl! PF! PF! Anfernee's got penis
flop! I can totally see it through his track
pants. It's all flappin against his pants and shit!"