Nick Jonas and Demi Lovato have reunited to work as judges on the X Factor.

Demi is a permanent judge, and she invited Nick to be a guest judge. He couldn't stop saying nice things about her!

She chose him because they grew up together and they both know how the music industry works.

Even though lots of things have happened between the two of them, they're close after all these years:

"There was always sort of that bond that goes beyond words. It’s great to see that 7 years into our relationship and friendship that we still have that."

"Even today, we were looking at each other across the room as the contestant was singing and we knew exactly what each other was thinking.'

Sources: Oceanup & Blogdelatele