All the buzz about Justin Bieber being an X Factor guest mentor are true!
Justin is seen in this video on the set of X Factor, helping during the judges' house round--he'll play mentor to judge L.A. Reid's group of singers.
Justin brings his immense experience as a pop star to the X Factor table, no doubt serving up some huge inspiration for the contestants who are hoping to make it big.
He tweeted to L.A., his real-life mentor: "long day but great day. @LA_Reid @ScooterBraun just like old times! Thanks"
Justin will help L.A. pick four contestants to compete in the final 16.
It's the bomb: Check out some hilarious photobombs and vote for your faves right here!