The 26-year-old star, who dated his "Camp Rock" co-star briefly in 2010, said they are really good friends, reported E! Online.
"She's family. We've known Demi for so many years. We're performed with her, toured with her. She's just incredible.
"It's not always the case. Sometimes you have to know when to fold the cards. I don't think of her as an ex. We're really good friends. We've gone through so much together and we're really close now," he said.