Demi Lovato insisted Ariana Grande duet with her on track she wrote

Demi Lovato was so impressed with the song Ariana Grande wrote for her, she insisted she appear on the track.

The Cool For the Summer star gave Grande an early preview of songs she was working on for what has become her new album, Dancing With the Devil... The Art of Starting Over, and Ariana offered to go away and write a new tune for her pal.

The result was Met Him Last Night.

Ariana agreed to sing on the track, but suggested she should just be a background artist.

"She was like..., 'I'll be like mystery, harmony lady'," Lovato tells Sirius XM's The Morning Mashup, "and I was like, 'I feel like the world would love to hear us together, like we should do that'. And she was like, 'Are you sure?' And I was like, 'Yes'. And so she added her vocals and, she’s just so talented, so great. I’m so grateful to have a friend like her."

Grande isn't the only guest on the new album, which dropped on Friday - Saweetie, Sam Fischer, and Noah Cyrus also feature.