Bella Thorne's Ex Gregg Sulkin Dating Twerk Master Lexy Panterra

Bella Thorne's ex Gregg Sulkin is getting a lot more booty these days, because he's moved on to twerk master Lexy Panterra.

The two got in some vintage shopping at the open air Melrose Trading Post in L.A. Gotta give Gregg a pat on the back ... they say one man's junk is another man's treasure ... and Lexy's gotta whole lot.

People thought Gregg and Bella had reunited when he started popping up all over her Instagram this summer after her Cannes charade with Scott Disick went awry.

It's interesting ... Lexy and Bella are good friends too, after appearing in Tyler Perry's "Boo! A Madea Halloween" We're guessing ... no hard feelings.