Meghan Trainor has confessed she enjoyed "one drunk make out" with Charlie Puth long before they locked lips at the 2015 American Music Awards.

The pop stars stunned viewers at the November (15) prizegiving when they enjoyed a steamy kiss after performing their collaboration Marvin Gaye, sparking rumours their studio chemistry had spilled over into real life.

They promptly shot down the speculation, insisting the smooch was all for show and there were just friends.

"We're friends and it's all part of my whole vision when I made Marvin Gaye, for people to hear the record and spontaneously make out with each other," Charlie explained to reporters directly after the MTV performance. "That was the goal tonight for the live show."

However, Meghan has sent gossips into a frenzy once more by revealing the staged liplock wasn't the first time the pals had kissed.

In a new interview with Seventeen magazine, the All About That Bass hitmaker confesses they had previously shared an intimate moment during a boozy recording session.

"Probably one drunk make out," she admitted. "I don't know if he's going to be mad I said that!"

"We were next to each other, recording a duet, and then I think I kissed him," she slyly recalled. "It was cool."

Despite the unexpected smooch, the singers chose not to take the relationship any further: "And then we never did it again. Ever," she insisted. "When we'd hang out, it would be like buddies."

Meghan has been single for four years, while Charlie was in a relationship at the time of their American Music Awards show. However, he revealed in January (16) he was no longer romantically involved.