Britney Spears Dances to Vanilla Ice, Justin Bieber in Japan, and More Celebrity Viral Videos

Our favorite social-media-savvy stars continued to delight us by sharing behind-the-scenes and candid clips online. From Britney Spears busting a move during The X Factor auditions to Brad Pitt’s brother starring in a clever ad campaign, we’ve gathered the best viral videos of the week in today’s PopSugar Rush. Subscribe to PopSugarTV! www.youtube.com Visit our website for more celebrity and entertainment news! www.popsugar.com Are we friends yet? Join us on Facebook! https Get the latest updates via Twitter! twitter.com