The two celebrate JC Chasez's birthday. Plus: Brad & George, Mischa Barton, Lindsay Lohan and more

MISCHA'S MYSTERY GUY

Solved! Despite rumors of a breakup with rocker beau Cisco Adler, Mischa Barton wasn't stepping out with a new love interest at London hot spot Umbaba recently: It was just her hairdresser pal Andy LeCompte.