Ina Wroldsen (unintentionally) exposed him last year after the song took off.
Quote:
“I’m a writer first, and in cases like this you put your emotions aside. I wrote that song with Disciples about 18 months ago. Calvin heard it, loved it and wanted to put it out as his own single.”
She's still credited as well so I don't see what tf y'all are complaining about? They probably just wrote it and he made a new composition / instrumental.