Wednesday

Caught in the Act!

09/09/2009 at 06:00 AM EDT

• Reese Witherspoon and Jake Gyllenhaal, treating the actress's kids Ava, 10, and Deacon, 5, to a cold treat at Twist in Brentwood, Calif. "Jake was great with the kids and they all shared little samples before deciding on flavors," an eyewitness tell us of the family frozen yogurt outing. But with dessert comes exercise – and earlier in the week, the couple took an exercise class at Burn 60, focusing on arm and shoulder work, as well as cardio. "The air conditioning wasn't on and in the 90 degree heat, Reese and Jake sweated and struggled like the rest of the class," an onlooker says, adding that the famous duo "seemed to enjoy" their workout.

• After celebrating her 10th wedding anniversary earlier this summer, Victoria Beckham spent an evening at West Hollywood's Chateau Marmont sans David Beckham. Posh was accompanied by an entourage – and she headed to a table in the back of the courtyard. According to an onlooker, Beckham was animated and chatting happily with her friends. Before leaving, she gave them kisses on both cheeks and took off arm-in-arm with an older man.

• Rihanna hit the pool and the casino while partying in Las Vegas over the holiday weekend. The R&B star spent time at Body English and XS nightclubs with pals, and then took her party poolside the next day, sipping drinks in a VIP cabana at the Hard Rock Hotel's Rehab bash while T-Pain performed.

• Also poolside: Khloe Kardashian, who sipped cocktails in the sun with new beau Lamar Odom at the Hollywood Roosevelt Hotel's Tropicana Bar. Before the reality star arrived, Odom briefly chatted up Gerard Butler, who was enjoying the music at the bar.

• Leonardo DiCaprio, browsing the swimsuit selection at Kitson Malibu while shopping solo at Malibu Lumber Yard. The actor popped into the store, greeted a salesperson and looked over the wares – but he left emptyhanded.

• By PERNILLA CEDENHEIM, MARK GRAY, EUNICE OH and SUSAN YARA

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