Last night a noticeably slim Kelly Osborne got on stage at an invite only performance with the Pussycat Dolls at the world famous Viper Room in Hollywood. The Pussycat Dolls were started by Robin Antin as a burlesque dance troupe by in 1995 before they signed a record deal in 2003 and became the musical group they are today.

Video after the jump….

images from justjared