, having a swinging good time – and working up a sweat – at the Jukari fitness studio in Los Angeles. The reality star tried out the customized workout
, which was created by Reebok and Cirque du Soleil and utilizes a trapeze-like bar, and seemed to have a good time: She mentioned to trainers that she'd love to bring her sisters in for a class. Kardashian also left with some Reebok dumbbells, kettlebells and mats.
would have been awkward! Jessica Simpson
just missed ex John Mayer
while dining at Katsuya Hollywood
with dad Joe
, mom Tina
and a posse of seven female friends. While the singers never crossed paths (Mayer stopped in earlier) Simpson did come face to face with another
musician ex: Adam Levine.
"He and Jessica briefly said hello and enjoyed their meals separately," says an onlooker of the two.
and Ashley Olsen
, taking in the New York city views at the Belvedere IX Save
Beatrice party inside New York's Cooper Square Hotel's penthouse. Joined by Mary-Kate's beau Nate Lowman
, the fashionistas also celebrated hockey star Sean Avery
's 29th birthday as he was presented with a cake that said, "Happy Pucking Birthday." Also there: Chloe Sevigny
Dita von Teese
, enjoying the music at pop star Mika
's secret show at the Roxy in Hollywood. Hosted by blogger Perez Hilton
(who shared a table with von Teese), the event began with a special burlesque performance before Mika launched into his hit "Grace Kelly" as the audience screamed. He also performed tunes from his forthcoming sophomore album, telling the crowd, "Help me to celebrate coming out of retirement."
Before mingling with their Real Housewives of New York City
costars Kelly Bensimon
and Ramona Singer
at the Conde Nast Traveler
Hot List bash at Pranna, Alex
and Simon van Kempen
caused a scene at a nearby post office while mailing their tax returns dressed in their red-carpet garb. Dozens of fellow
taxpayers spotted the duo and began pointing, shouting and snapping photos!
By JENNIFER GARCIA, BRETT MALEC and LESLEY MESSER
Want to see where the celebrity action goes down? Tour all of the Celebrity Hot Spots.Thursday's Caught in the Act >