The 'Jealous' singer has been writing songs with the 31-year-old star, but he has suggested that fans might find it difficult to pick her out in the finished tracks.
Speaking to Billboard magazine, he said: ''Skylar Grey ... is one I'm very excited about people to hear the music we wrote together.
''She's always very generous with her time, and I just love the sound of her voice, so sometimes I just try to sneak her in there and keep her vocal tracks for my own use [Laughs]. I don't think there will officially be a song with her, but you'll probably hear here in the background if you listen close enough.''
The 25-year-old musician got his big break as part of The Jonas Brothers - alongside siblings Joe and Kevin - and he also opened up about all he has learned both in a band and over his own solo career.
He added: ''I think just life experience and experience performing - everything from the time with the brothers to the last four years solo, I think I've just grown into my own as an artist and what I want to say. I think the fact that I'm able to still tell my stories as a solo artist and write my music really helps. It just feels good to take those steps forward, to be affirmed in that way, and to still be here so many years later. I feel really grateful and I'm just trying to enjoy the ride.''
Meanwhile, Nick enjoyed a festive reunion with Joe and Kevin over Christmas, with the latter hosting a gathering that turned into something of a reunion.
Nick recently told Us Weekly: and they all ended up singing around the fire with acoustic guitars.
He said: ''Kevin has this really nice kind of office in his house and there's a couple acoustic guitars laying around. And we had this moment where we looked at each other like, 'This is what people think is happening right now.' Like at the end of that Christmas, we end up by the fire, the three of us, with acoustic guitars, singing, playing some of the old songs.''