...Britney's dancer buddies were cutting up a rug at Parc! We spotted TJ (who you may remember from his numerous appearances during Britney's post-split phase) partying it up at Hollywood's hottest spot - naturally, we asked him why he could be found in Tinseltown rather than San Diego, but he just smiled, shrugged and said he had to attend a birthday party!

And what a star-studded event it was: in addition to both Paris and Lindsay, we also spotted underage rager Rumer Willis, Justin Long dishing the dirt about his pregnant girlfriend, October Road hottie Laura Prepon, and Crispin Glover sporting a Posh Spice-esque bob!