Singer Charlie Puth was ordered to keep kissing Meghan Trainor at the end of their American Music Awards performance.

The pop stars performed hit duet Marvin Gaye at the ceremony in November (15), and shocked fans by engaging in a steamy smooch at the end of the song.

However their supporters were left disappointed when the pair confirmed they are just good friends, and Charlie has revealed it was a longer kiss than he had originally anticipated.

"Everyone thinks it's this big relationship thing, but it's just that at the end of our Marvin Gaye video, we leave it on a cliffhanger, so we thought we'd put everyone out of their misery and kiss," he explained to Britain's Fabulous magazine. "The producer was in my ear saying, 'OK, keep going, keep going," so that's why it went on for so long - I was just obeying orders!"

Charlie, 24, was excited to perform with Meghan, 22, and told One Direction heartthrob Harry Styles about what they had planned before they took to the stage.

"He just smiled and said: 'Well, isn't that lovely'" he added. "He's so cool and polite."

While the See You Again singer and Meghan are just good pals, the star really values her friendship and would never want to jeopardize it.

"We love to recite lines from South Park and try to out-gross each other," he laughed. "I always think that's the mark of a good friendship if you can be really vulgar."

For now, single Charlie is just focusing on his career, but would like to be in a relationship one day.

"I'm on the road a lot, though, so it would make things hard and require her to put her life on hold," he sighed.