Peter Kramer / Invision/AP 1 / 14
Peter Kramer / Invision/AP 1 / 14

Marital woes won't keep her from celebrating Halloween!

Despite a dramatic, difficult month -- and an increasingly skinny frame -- Demi Moore was in a festive mood Friday night, Oct. 28, 2011.

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Weathering the storm of husband Ashton Kutcher's fling with a 22-year-old, Sara Leal on their sixth wedding anniversary Sept. 24, Moore, 48, was among the A-list revelers at actor Mike Meldman's Halloween bash in Beverly Hills on Friday.

With Kutcher, 33, nowhere in sight, Moore and a crew of gal pals drank and partied late into the night alongside such stars as Cameron Diaz, directors Eli Roth and Todd Phillips plus reality star Brittny Gastineau.

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"She was having fun, [and] she drank," a source tells Us Weekly. "But she wasn't the belle of the ball. Everyone at the party was drunk!"

Last Thursday, a somber Kutcher hit a GQ event in NYC without his wife --- but Moore seemed to be on his mind. Kutcher wore his wedding ring and, when video monitors played footage of him with his wife, the "Two and a Half Men" star watched with rapt, serious attention.

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He even told a fellow reveler he was "doing OK" despite the ongoing turmoil.

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