Selena Gomez makes a cameo in the official video for a song she used in a dance video earlier this year.
The song is "Everybody Knows (Douchebag)".
She pops up at the 4:28 mark -
And just to refresh your memory, Selena & her friends used this song in a dance video shortly after her and Justin Bieber broke-up. Hmmmmmmmmmmmmmm -