The temporary false attraction/chemistry that occurs after a couple goes to prom. The couple usually starts dating or hanging out after the event, and the "relationship" becomes Facebook official in a matter of days.
The PPA-affected couple usually breaks up within a month or two.
John: Jane, you look BEAUTIFUL.
Jane: *blushes* Oh, thanks John.
*24 hours later*
John: Hey Jane, you wanna go out sometime? Like a date? *planning on getting action soon*
Jane: Sure! *daydreams future life together as a result of suffering from Post-Prom Attraction (PPA)*