Pop princess Britney Spears returned to the stage to sing the last verses of “S&M” with Rihanna, who sexed up the stage in a hot bondage inspired outfit as she kicked off the show at the 2011 Billboard Awards held at the MGM Grand Arena in Las Vegas, Nevada on Sunday (May 22)- watch video below.

2011 Billboard Music Awards Winners (FULL List)

Britney and Rihanna wore similar outfits – one white and one black with their hands chained. Britney, who made her grand appearance with a black bunny mask, did one heck of a poor job lip-synching her very small part of the show.

However, the “Hold It Against Me” singer looked a lot more comfortable and more energetic on stage. Rihanna and Britney ended their performance with a steamy pillow fight. HOT!

Rihanna & Britney Spears “S&M” At Billboard Awards Video