Olsen treats herself to a day of beauty at a spa in Beverly Hills. Plus: Mischa Barton, Ashlee Simpson, Rihanna and more

LEAN ON ME

Ashlee Simpson holds tight to her boyfriend Pete Wentz during the release party for her album Bittersweet World Tuesday at New York hotspot Marquee. Simpson, who performed on an upstairs balcony overlooking the dancefloor, sang a trio of songs from the album, including "Outta My Head (Ay Ya Ya)."