Cassie showed off her sexy figure in a white bikini on Miami Beach over the weekend with model BFF Kerry Morgan, enjoying a girl's day out for some fun in the sun.

The model-turned-singer, rumored to be dating Sean "Diddy" Combs, was sporting a huge rock on her left ring finger, making us wonder if Diddy popped the question.

Cassie posted a photo of her left hand with the same ring to her instagram page about a year ago, but she didn't even mention it, simply writing, "Fresh Nails!"

The couple have kept their reported relationship out of the public eye, and last fall the singer tweeted that rumors that the two were engaged were "bulls**t" and she was already committed to someone.

Three weeks later she tweeted her love for Combs after GQ magazine titled the video shoot that accompanied a photo spread she did "Diddy's Girl."