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Less than two months after he announced his separation from his wife of 11 years, Sean Penn hit Sunday night’s Oscar party circuit with a new blonde beauty on his arm: model Petra Nemcova.

The two arrived together (or, at least, simultaneously) at the Elton John AIDS Foundation screening party. Although they separated briefly – he did an interview while she posed for pictures – they eventually reunited for the cameras, as Penn wrapped his arm around her for a few photos.

So, are they dating? The actor, 47, and model, 28, avoided any clear-cut PDA. And when asked about her escort, Nemcova, wearing a custom-designed Roberto Cavalli dress, would only tell PEOPLE, “Yes, we are friends. He is on the advisory board of my charity.”

Friends who’ve been spending quite a bit of time together: A source confirms that the two also hit L.A. hotspot Villa the night before.

Penn announced his separation from actress Robin Wright Penn just after Christmas. In the divorce papers, both cite “irreconcilable differences” and ask for joint legal and physical custody of their two teenagers, Hopper Jack, 14, and Dylan Frances, 16.

Last year, Nemcova made the Oscar party rounds with then-boyfriend James Blunt. But she and the “You’re Beautiful” singer split shortly afterward.

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Pictured: Pink (above), Beyonce, Brad Paisley and wife Kimberly Williams, Carrie Underwood, Chris Brown, Chris Daughtry and wife, Jay-Z, J.C. Chasez, John Mayer, Kat Von D, Kelis, Michelle Willams, Petra Nemcova & Tia Carrere

She’s always cute.  Man, I hate her.

• Petra Nemcova
• Kristin Davis
• Lisa Kudrow
• Molly Sims

She’s almost unrecognizable!