Britney Spears & Katy Perry's Secret Collaboration Revealed!

wochit entertainment
July 28, 2013 AT 8:01 PM
Who knew Britney Spears and Katy Perry have made music together? It turns out Perry actually sings on Spears.The catchy pop tune, written by frequent Perry collaborator Bonnie McKee, is played over the end credits of the Smurfs 2 movie.