Charlie Puth and Selena Gomez have already collaborated on music together and worked out some tour plans in the future. They’re not dating, but they’re good friends, and the singer totally has her back — even when it comes to her former relationship. The “See You Again” singer totally dissed Justin Bieber while performing his track with Selena, “We Don’t Talk Anymore.” There’s no second-guessing it; his comment is pretty brutal.

Midway through his performance, Charlie said, “F*** you, Justin Bieber,” and a fan captured it all on video!