Thursday

Caught in the Act!

01/22/2009 at 06:00 AM EST

• In the mood for a party, Audrina Patridge got kissy with a mystery man in a red plaid shirt at West Hollywood's Coco de Ville. Throughout the night, he smooched the Hills star on her neck and, at one point, even picked her up – though he stumbled and dropped her, an onlooker tells us. But Patridge didn't miss a beat: She picked herself up and threw up her hands as the deejay played Obama-related tunes. The reality star also grabbed some drinks and chatted with her female friends before calling it a night.

• Jennifer Aniston grabbed her usual table at her go-to spot, the restaurant in L.A.'s Sunset Tower Hotel, for a girls' night out. Tucked away in the corner, Aniston kept a low profile. Still, she seemed to be the life of her party: After making a trip to the patio, the actress made her friend laugh so loudly that she threw her head back in the air.

• Fresh from her performance at the Neighborhood Ball, Mariah Carey offered hubby Nick Cannon a semi-private one while partying after 1 a.m. at the George Town Club in Washington, D.C. "She sang to him along with what the deejay was spinning," an eyewitness tells us. Then, it was Cannon's turn. "He picked up the mic and started to rap to her," the eyewitness says. While there, the duo enjoyed some drinks – red wine for her, a ginger ale for him – and cuddle time: "They were very affectionate," another source says, "he had his arm around her and she was kind of nestled into him."

• Also in D.C. for the inauguration: Usher, who indulged in a late-night treat at 50-year-old institution Ben's Chili Bowl. The singer stopped in for some grub – and a chocolate milkshake. (Read about all the concerts, parties and balls from D.C.!)

• How I Met Your Mother's Alyson Hannigan, taking a pilates class with hubby Alexis Denisof at Rapid Rehab Pilates in Brentwood, Calif. According to an eyewitness, the expectant actress "seemed very happy" as the couple strolled hand to the studio, toting matching water bottles. Earlier in the day, the sitcom star picked up lots of fruit – including oranges – at the Farms, a grocery store in Santa Monica.

• Alicia Keys, sharing girl talk and cocktails with a female friend at the Stone Rose inside the Sofitel in Los Angeles. The singer sipped on shiraz while her pal drank a cosmo.

• By PERNILLA CEDENHEIM, JENNIFER GARCIA, ARNESA A. HOWELL, KRISTEN MASCIA and ABBY STERN

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