updated 08/18/2009 AT 2:00 PM ET
•originally published 08/19/2009 AT 6:00 AM ET
After a late-night 21st birthday bash at Tao Las Vegas, Rumer Willis followed up the festivities with a more intimate celebration the following evening: She held a family dinner at Koi inside the Planet Hollywood Resort & Casino. Joined by dad Bruce Willis, his wife Emma, mom Demi Moore, stepdad Ashton Kutcher and her sisters Tallulah and Scout, the starlet pre-selected dishes from the restaurant’s menu for the meal. The group – which also included family friends – assembled in the Fountain Room for the private feast, which ended with Rumer blowing out all the candles on her cake after a “Happy Birthday” serenade.
Before coming to Vegas to celebrate with Rumer, Ashton and Demi hung out with close pals Soleil Moon Frye and her hubby Jason Goldberg at a Modart magazine party at L.A.’s Thinkspace Gallery. The happy couple sipped on red wine, browsed the artwork and hung with German street artist Nomad.
In the Big Apple, Rihanna celebrated her assistant’s birthday with a bash at Buddakan. The singer and her pals were all decked out in party hats. “She sang ‘Happy Birthday’ with the whole crew and everything,” a source says.
Continuing her baseball-themed road trip, Kate Hudson teamed up with her New York Yankees star beau Alex Rodriguez for dinner at San Francisco’s Epic Roasthouse. The two grabbed a back corner table and cozied up over oysters, caviar, filet mignon, a whole fish and some sides.
Michelle Trachtenberg, chatting up revelers at a dinner celebrating the Web site Shopbop.com at New York event space The Smile. “She was super-social,” a guest says, adding that the actress talked a lot about fashion. “She was totally the life of the party.”
By ALEXIS CHIU, JENNIFER GARCIA, MARK GRAY, LESLEY MESSER and ULRICA WIHLBORG