Justin Bieber Plays Onstage Prank on Willow During ‘Whip My Hair’ Performance

Do we smell a prank war brewing? Last night, Justin Bieber and his cohorts played a lighthearted prank on tourmate Willow during her performance of 'Whip My Hair' in Manchester, England. Bieber was retaliating after Willow tried to play a prank on him, and the 'Baby' singer warned the Twitterverse of his intentions before the show on Sunday. He wrote, "So the other day @officialwillow decided to try and prank me. PRANK ME!! lol. well now is PHASE 1 of my REVENGE!! Manchester get ready!!"

As Willow belted out 'Whip My Hair' to the roaring crowd, Bieber's manager, Scooter Braun. and his swagger coach, Ryan Good, invaded the troop of backup dancers sporting long colorful wigs. The two men then proceeded to whip their hair alongside Willow, who had trouble keeping a straight face as she sang her smash hit. She then broke down, laughing into the mic as she said, "Our new back-up dancers!"

Bieber himself soon appeared onstage, and the 17-year-old proceeded to wail on a cowbell next to Willow. As she reached the chorus, all three of the gents began ferociously whipping their hair along with Willow and her female backup dancers.

Willow's older brother Jaden Smith soon joined in the madness onstage -- he was sans wig, however, since the 12-year-old has his own whippably long locks. Bieber and Smith soon exited the stage, but Good and Braun apparently stayed for the rest of the song.

Later, Bieber tweeted, "Me and @officialjaden and @scooterbraun and @thatrygood #PRANKSTERSONTHELOOSE." Willow obviously enjoyed the prank, taking to her Twitter page to write, "My big brother's Justin and Jaden pranked me on stage tonight...#payback!!!" We are anxious to see what Willow has cooking up for the next round of pranks!

Watch Justin Bieber Prank Willow Onstage