People magazine reported that Bieber, his manager Scooter Braun and "swagger coach" Ryan Good surprised Smith onstage during a performance in Manchester, England. They came out wearing neon-colored make up and hair extensions and danced onstage while Smith sang her hit song "Whip My Hair."
Bieber, who refers to Smith as his "little sis," pulled out a cowbell and banged on it as Smith's older brother Jaden Smith emerged and whipped his hair next to her.
The Huffington Post said their timing was a bit off as they missed the chorus, the time of most energy in the song.
Smith, according to PopEater , didn't miss a beat and just continued with her song. That didn't mean she would forget it.
My big brother's Justin and Jaden pranked me on stage tonight … #payback!!!" Smith posted to her Twitter page.
"They got me, but it is not over; revenge is sweet and is served on a cold dish," PopWatch reported she said in a video diary of the prank.
Smith, 10, is the daughter of actor Will Smith and Jada Pinkett Smith. She made her acting debut in the movie "I Am Legend," which also featured her father as the star.
She launched her music career in 2010.
As far as her revenge on Bieber, it may have to be on another tour. She posted on Facebook that she was about to have her last sound check and last show.
"Thank you for taking such great care of me," she posted. "Well, I am going to be home wishing on was on tour forever!"
