NBA star Chandler Parsons has a big fan in Bella Thorne ... they're not only going to see movies together, they also shared a kiss in Mexico.

Thorne was in the crowd at FedExForum sporting a Parsons jersey on Tuesday when the Memphis Grizzlies played the Suns ... she also had Chandler's #25 painted on her face.

The next night, Thorne and Chandler (and another female friend) hit up the movies together to see "Get Out."

Oh, and that kissing pic -- that was taken in Mexico over All-Star Weekend.

Sources connected to the two say they're "just friends" ... but it seems they're definitely into each other.