Nicki Minaj's Ex Safaree Samuels -- I'm Over Dat Ass ... And Onto K. Michelle's Booty

You gotta hand it to Safaree Samuels, he knows what he likes -- because TMZ has learned he has moved on from Nicki Minaj to a new singing booty queen ... K. Michelle.

According to our K. Michelle sources, she and Samuels (who did not take the breakup with Nicki well) have been getting much closer lately ... talking and texting every night.

We're told the duo spent two hours together in the VIP area of NYC club Stage 48 on Valentine's Day -- and Samuels followed up this week by sending a bouquet of sunflowers ... her favorite.

Our sources say they're not official, meaning exclusive ... just yet -- but this video K. Michelle posted of herself twerking to Safaree's new song has to count for something!