"There was never a boring moment" on the set of Princess Protection Program
, Selena says of her and Demi's first movie together, which debuts on the Disney Channel June 26. Shot in Puerto Rico in 2008, the film is about Princess Rosalinda (played by Demi), who—after her country is invaded—has to be watched over by a secret organization (Selena plays Carter, the head honcho's daughter) to keep her safe. The girls agree that working together was a blast. "We don't really think of it as work," says Demi. Especially after hours—they had sleepovers in Demi's hotel room! "I had my clothes there half the time," says Selena. "We did everything together."