Mayweather vs. Pacquiao -- Gamblers Betting on Bieber ... In Crazy Prop Bets

Wanna bet if Justin Bieber will WEAR A HAT during his walkout with Floyd Mayweather??

Well, now you can ... because betting websites are seriously TAKING ACTION on the pop star in some crazy new prop bets for the fight..

We spoke with the people over at BetOnline.ag who tell us Bieber is a hot topic when it comes to prop bets ... which is why they're taking action on the guy. For example:

Will Bieber wear sunglasses during the walkout?
Yes -380 No +260.

Translation -- it's so likely he'll rock shades, you have to bet $380 to win $100.

There's more ...

Will 50 Cent walk out with Mayweather?
Yes +185 No -275

Jamie Foxx's National Anthem time
Over 94 seconds -120
Under 94 seconds -120

Filipino National Anthem time
Over 76 seconds -120
Under 76 seconds -120

It sounds ridiculous, but prop bets are HUGE during major sporting events!