Jeff Vespa / WireImage 1 / 7
Jeff Vespa / WireImage 1 / 7

Batman gets a birthday bash! Days before news broke that Ben Affleck would be playing Batman opposite Henry Cavill's Superman in the "Man of Steel" sequel, the Oscar winner celebrated his 41st birthday with family and friends. Affleck's wife, Jennifer Garner, coordinated the party at their home in L.A.'s Brentwood neighborhood on Sunday, Aug. 18.

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"There were about 30 people who showed up around 2 p.m. for an afternoon party," an eyewitness tells Us Weekly. "There were kids running around in the yard having a blast." Adding, "It was a relaxed afternoon and people didn't bring gifts. They all started to leave after dinner around 6 or 7 p.m."

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The intimate get together also included the "Runner Runner" star's BFF, Matt Damon, who attended with his wife, Luciana, and their four daughters Isabella, 6, Gia, 4, Stella, 2, and Alexia, 14, Luciana's daughter from a previous relationship. The "Elysium" actor, 42, and his wife of nearly eight years, recently moved from New York to Los Angeles with the family.

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The "Good Will Hunting" co-stars have been able to spend more time together since the move, and their wives have become closer. "Jen likes to throw parties at the house; she has a clique in L.A. that Luciana is getting introduced to," another source adds.

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