Sofia Richie Flaunts White-Hot Bikini on WaveRunner in Miami

Sofia Richie looks like she's auditioning for the next "Baywatch" movie, but truth is she's just having some cheeky, ab-tastic fun.

Sofia took a break from flaunting what the good Lord gave her to fly solo on a WaveRunner Friday in Miami. She's down there with her bf Scott Disick, and for the life of us ... we can't see any reason for him NOT to be with her for this outing.

He's obviously a lucky guy, but Scott ... plan your time better, bro!