Paris Hilton and Britney Spears by Jeffrey Mayer/WireImage.com Paris Hilton and Britney Spears by Jeffrey Mayer/WireImage.com

Britney Spears - who over the weekend reportedly celebrated her 26th birthday with drinks, dancing and Paris Hilton - has pulled out of a cover shoot for Rolling Stone out of fear that publisher Jann Wenner would pull a Nick Lachey on her. (Last year, Jessica Simpson's ex posed for RS only to have the shoot instead used for sister mag Us.) "[The cover story] was going to be a good platform for her music to be taken seriously... but she refused to get screwed by Wenner," a source tells Page Six. "They kept negotiating [and] it got nasty."

A rep for RS pooh-poohs the extent of the deliberations.