By Jessica Goodman
Updated November 22, 2015 at 12:00 PM EST
Credit: Lester Cohen/WireImage

Meghan Trainor and Charlie Puth gave AMA viewers a surprise Sunday night when they full on made out after performing their recent singles “Like I’m Gonna Lose You” and “Marvin Gaye.”

As the song ended, they just went for it:

Trainor and Puth have worked together since last year, when he made a cameo on her single “Dear Future Husband.” Earlier this year, Puth told EW they met at a party in the Hollywood Hills. “I played her a very early demo version of ‘Marvin Gaye,'” he said. “And she memorized the song and sang it in the studio a week later. … She’s taken me on and introduced me to her fans — they call themselves the Megatrons, and they’ve kind of adopted me.”

Puth also joined Trainor’s tour earlier this year, but she had to call off the run due to a vocal hemorrhage.

When asked about their relationship, a rep tells EW in a statement, “They’re just friends.”

Check out our acoustic session with Puth below: