Watch Britney Spears' Video Cameo on Madonna's Sticky & Sweet Tour

A clip of Britney Spears ' video segment from Madonna 's Sticky & Sweet tour has hit the web. In the segment (which played while Madonna sang "Human Nature"), Spears is trapped in an elevator and whispers the lines “express yourself, don’t repress yourself." The video ends with her saying, “It’s Britney, b—-.” Spears and Madonna famously locked lips at the 2003 MTV Video Music Awards. See Madonna's biggest scandals. Madonna kicked off her tour Saturday night at Cardiff's Millennium Stadium in Wales, opening with "Candy Shop." In addition to Spears, the 40,000-member audience also enjoyed onscreen appearances by Kanye West and , who dueted on "4 Minutes." (link)