Meghan Trainor, Charlie Puth lock lips on AMAs stage

Um ... what just happened?

After performing throwback single Marvin Gaye at the American Music Awards Sunday night, Charlie Puth and Meghan Trainor took their "get it on" lyrics to heart — smiling and kissing as the show went to commercial.

We weren't the only ones confused by the steamy makeout sesh. Luke Bryan called out the pair while accepting his country male artist award, saying he was "still laughing" about the onstage smooch.

People on Twitter were equally taken aback. After all, this is the first time Puth and Trainor have gone public with their relationship.

Congrats, guys?