Marshmello appears to be teasing a collaboration with Demi Lovato.
The anonymous DJ has posted a snap of himself on the telephone and hinted that he's either already recorded or has asked the pop star to feature on his new track.
He simply captioned the post on Instagram, which he tagged the 27-year-old singer in, with: "hello? demi? (sic)"
Back in 2017, a song by the pair called 'Love Don't Let Me Go' was registered to ASCAP, with Marshmello, Louis Bell, Brian Lee, Ali Tamposi, and Andrew Watt given songwriting credits, but it's yet to be officially released.
Marshmello recently dropped 'Be Kind' with Halsey, whilst his other collaborations include 'Tongue Tide' with Yungblud - Halsey's ex-boyfriend - and blackbear and 'Been Thru This Before' with Southside featuring Giggs and Saint Jhn.
As for Demi, she released the Sam Smith duet 'I'm Ready' in April, and the lead single from her upcoming seventh studio album, 'I Love Me', the month before.
Last June, Demi said she will share her "side of the story" on her follow-up to 2017's 'Tell Me You Love Me'.
The 'Sorry Not Sorry' singer said it will give her the opportunity to "be as open and honest as possible" without worrying about what other people will think.
She shared a shrugging emoji on her Instagram Story and wrote: "You know what's great about making an album?
"You get to say anything you want, be as open and honest as possible and finally tell your side of the story regardless of who might not like it."
The pop star - who suffered a drug overdose in July 2019 - announced a month earlier that she had joined forces with manager Scooter Braun - who is well-known for having represented the likes of Justin Bieber and Ariana Grande.
She said at the time: "GUYS!!!!!!! Dreams came true today for me. I officially have a NEW MANAGER!!! And not just any new manager but the one and only @scooterbraun!!!!
"Couldn't be happier, inspired and excited to begin this next chapter with you Scooter!!! Thank you for believing in me and for being a part of this new journey. Let's DO THIS!!!!!! (sic)"
Although Demi is yet to reveal any firm details about the album, she previously teased her fans with a photo of herself in front of a microphone in the studio.
She captioned the selfie: "Making magic."