Cardi B Spotted in Cocktail Dress, Out With Stefon Diggs on Valentine's Day

Cardi B continues to fuel romance rumors with Stefon Diggs ... 'cause the two painted Miami "Bodak Yellow" late Friday night.

TMZ has obtained videos and photos showing the rapper and the NFL wide receiver arriving to a Miami hotel in the wee hours of Saturday morning ... with Cardi dressed up all sexy in a revealing dress.

Check it out ... Cardi's dress is clinging to her frame -- and, when she bends forward, her entire bust is on display. Diggs dressed in all-red for the occasion, looking comfortable in a jacket and baseball cap.

Eyewitnesses tell TMZ ... Cardi and Stefon got back to the hotel around 1:54 AM. It's safe to say the two spent Valentine's Day on the town together.

This isn't the first time the pair has been spotted together. Just last week Cardi and Stefon were spotted together at a New York City nightclub.

Cardi's had a big month ... throwing it back at a series of parties down in New Orleans for the Super Bowl -- though she wasn't spotted with SD down in the Big Easy.

Of course, Cardi filed for divorce from Offset in August of last year -- and, while rumors of infidelity plagued them over the years, sources told us they simply grew apart.

That said, a couple months after the filing, Cardi did say she wanted Offset to get hit by a bus ... so, co-parenting might prove a bit tricky moving forward.