Demi Lovato surprised fans by joining the Jonas Brothers during their first show on the "Jonas20: Greetings From Your Hometown Tour" in New Jersey Sunday.

The band — consisting of brothers Joe, Nick and Kevin Jonas — kicked off their 20th anniversary tour on Sunday at MetLife Stadium in their home state of New Jersey. But to make it more special, they surprised their fans with some special guests throughout the show, including Demi Lovato .

On Sunday, Demi Lovato joined the Jonas Brothers on stage in New Jersey for the opening night of the JONAS20 tour, dazzling in statement-making rhinestone-covered jeans. For the “Camp Rock” reunion, Lovato, 32, slipped into a pair of slouchy crystal-adorned Acne Studios jeans ($1,400).