Spotted!

Kourtney Kardashian and Lo Bosworth spotted hanging out at the Sierra Mist Ruby Splash launch party at the Fontainebleau Hotel in Miami Beach on March 21.

Stephanie Pratt carrying Treesje's Asher in Electric Blue on Saturday afternoon, while out dining with future sister-in-law Heidi Montag in Los Angeles.

Brothers & Sisters star Rob Lowe celebrated his 45th birthday at San Ysidro Ranch's The Stonehouse restaurant in Montecito, Calif. on March 20. After dinner, Rob his guests (including a pretty mystery brunette) enjoyed chocolate birthday cake with a handful of other guests. "Rob was so happy," a diner tells OK! of the Montecito local.

Rob and his cake: