Bella Thorne And Gregg Sulkin -- She's Underage, He's Not, They're Dating and it's Cool

Bella Thorne is 17 and Gregg Sulkin is 23 ... and they're dating, and it feels very Tyga/Kylie.

The duo hit the Teen Choice Awards doing very couple-y things -- holding hands, kissing on the cheek and calling each other "baby" and "sweetheart."

Source close to both Bella and Gregg tell us they are definitely "dating." What's more, we're told their families are cool with the relationship, in large part because she's almost 18.

There were a lot of people who saw them last night on the show and felt it was inappropriate, especially on a show like the Teen Choice Awards.

BTW, under California law they can do a lot. The only thing the law prohibits is penetration, which is defined broadly.