Emily VanCamp and Josh Bowman
Sara De Boer/StarTraks
12/04/2012 at 06:00 AM EST
and her costar – and off-screen boyfriend – Josh Bowman
attended the Mending Kids International Four Kings & An Ace Charity Poker event at West Hollywood hotspot The London on Saturday.
"Emily looked stunning in a nude and black cocktail dress while Josh complimented the outfit with a chic suit and tie," an onlooker at the event, sponsored by El Cartel Tequila, tells PEOPLE. "After laughing over their popcorn, the pair headed to one of the VIP rooms where the celebrity poker tournament was underway."
At the celebrity poker tournament – where player tickets were $10,000 a person! – Robert Downey Jr., Jodie Foster, Sean Penn, Mel Gibson and Gene Simmons played for a good cause.
cast members including Madeleine Stowe, Nick Wechsler, Gabriel Mann, Aiden Mathis, Margarita Levieva, Connor Paolo and Ashley Madekwe were also on hand to enjoy casino games and cocktails.
– Melody Chiu