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Who says exes can't become friends?

Kate Hudson and Owen Wilson had a surprise reunion in the front hallway of the Vanity Fair Oscar party at Sunset Tower in West Hollywood, Calif., on Sunday.

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The former couple, who dated from 2006-2007 after meeting on the set of "You, Me and Dupree," "totally had a moment," a partygoer tells Us Weekly exclusively. "They hugged and kissed on both cheeks."

Hudson, who welcomed son Bingham in July 2011 with fiance Matt Bellamy, asked her ex, Wilson, "Are you doing well?"

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Wilson, 43, said he's "doing great" and the two stars "talked about their kids and how old they are now," the partygoer reveals. (Wilson and Jade Duell welcomed son Robert Ford in January 2011; Hudson also has son Ryder, 8, with ex-husband and Black Crowes frontman Chris Robinson.)

"They pulled out their phones to show each other pictures," the partygoer tells Us. "They both oohed and ahhed over them."

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Hudson, 32, was in great spirits throughout the night. In addition to chatting up Wilson, the "Something Borrowed" star (who wore a vintage Versace gown) made amends with actress Cameron Diaz, 39. The famous blondes -- who had a falling out in 2010 when Diaz began dating Hudson's ex Alex Rodriguez -- sipped champagne and happily posed for pictures together.