After Prank, Willow Smith Promises Revenge on Justin Bieber

He may have gotten a haircut, but Justin Bieber proved that he can still whip it, surprising Willow Smith during her recent 'Whip My Hair' performance, PEOPLE reports.

Touring as the 'Baby, Baby, Baby' singer's opening act, Smith was performing her fame-making hit when Bieber and her brother, Jaden, appeared on stage to show off their own head banging skills. Video of the prank shows a surprised Smith, but the pro didn't miss a beat and continued with her routine.

The prank was all in good humor, and we've got a feeling that this isn't the first time Bieber tried to pull a fast one on Smith, who he calls his "little sis."

Both Smith's manager and "swagger coach" participated in the prank for which the pair got Willow-fied -- they made their onstage debuts in makeup and colorful braid extensions inspired by the '21st Century Girl.'

But just because the boys made the first move doesn't mean Smith is not ready to retaliate. In a video diary of the prank, she tells the camera, "They got me, but it is not over; revenge is sweet and is served on a cold dish."

The fashion forward 10-year-old later tweeted, "My big brothers Justin and Jaden pranked me on stage tonight ... #payback!!!"

Watch out boys, it looks like her hair isn't the only thing Smith will be whipping into shape.

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