Watch: Justin Bieber joins Selena Gomez on stage, covers Justin Timberlake
The blonde-coiffed singer gave a squeeze to a surprised (or "surprised?") Gomez before launching into a guitar-led "Favorite Girl," appropriately, and then covered a little bit of Justin Timberlake's "Cry Me a River," a take he's tackled before.
Video below of said incident, replete with the screams of thousands of girls.
The pop singer is prone to surprising his fans. He made a little appearance on a tiny show called "The Daily Show with Jon Stewart" before, and also bombed a concert of Ernie Halter's after he covered the indie songwriter's "Come Home to Me."
Meanwhile, this weekend it was revealed at Comic-Con that the Bieb wanted to be on "Vampire Diaries," plus MTV said that he's written into Pee-wee Herman's forthcoming Judd Apatow-produced film. Because God is apparently SEO-friendly.