Justin Bieber Pants Fall Down [VIDEO]: Selena Gomez's Shirtless Ex's 'Believe' Tour Wardrobe Malfunction, Almost Loses Red Leather Pants Onstage, Black Boxer Briefs Exposed

Justin Bieber sure knows how to make his Beliebers croon. During a recent "Believe" tour pit-stop in Jacksonville, Florida, the Biebs was singing onstage when he almost lost his pants! Selena Gomez's shirtless ex was donning a pair of tight leather red trousers... and apparently the excitement of the crowd impelled them to to fall down, exposing a good chunk of the pop megastar's black briefs! Check out the amusing "wardrobe malfunction" clip below.

As the 19-year-old singer was belting out lyrics to his hit tunes "Boyfriend" and "Baby," his pants continued to creep down lower and lower:

That bright (half) ensemble was a major fashion blunder to begin with... the pants falling down was just icing on the cake. That awkward crotch-grabbing just makes things that much more amusing.

How does Biebs' onstage wardrobe mishap compare to ex-girlfriend's, Selena Gomez?

Selena Gomez Wardrobe Malfunction Roundup [PHOTOS]: Nip-Slip vs. Underwear Flash, Sexier Fashion Mishap for Justin Bieber's Ex? [POLL]