Britney Spears claimed her first female S&M celeb victim at her show in Las Vegas last night: Super-fan Nicole Richie!

The fashionista was pulled onto the stage and walked around like a dog on a leash during the pop star's "Freakshow" performance on Tuesday night.

Looking at the video above, it seems like Richie reallllly enjoyed herself -- and Spears made sure to thank her for joining the performance after the show on Twitter.

Richie follows in the footsteps of Mario LopezLance Bass and Britney's boyfriend David Lucado.

While that part of the show was pretty great, there's another video making the rounds showing Spears forgetting to sing during "Alien." And though her microphone isn't to her mouth, you can still clearly her her voice.

Yep, total lip-sync FAIL! Whoops!

Have you gone to see Spears' "Piece of Me" show in Vegas yet? Check out our review here

Hot Videos