A mental disorder afflicting teenage girls, characterized by extreme highs at the sight of Justin Bieber with marked lows or depression upon hearing of his association with Selena Gomez.
Boy: OMG, Justin Bieber is dating Selena Gomez?!
Girl: WAAAAHH! (The Snooki waahh) FML! I need a drink!
Boy: Someone has Bi-eber-Polar Disorder,
Girl: STOP MAKING FUN OF MY MEDICAL CONDITION!