Demi Lovato joins Jonas Brothers on stage at MetLife Stadium

The Jonas Brothers took a trip down memory lane as they kicked off their 20th anniversary tour.

On Sunday, Aug. 10, Kevin, 37, Joe, 35, and Nick, 32, had a huge surprise for fans as they performed the first of their JONAS20 shows at MetLife Stadium in their home state of New Jersey with a very special guest.

The trio reflected on their 2008 hit Disney movie, Camp Rock, with Joe — who played pop star Shane Gray in the film — belting out the song "Gotta Find You" before he introduced his former costar Demi Lovato, 32, who played Mitchie Torres, to the stage.

The pair, who played onscreen love interests as well as having a short-lived relationship in real life in 2010, sang the movie's hits, "This Is Me" and "Wouldn't Change a Thing" together.