Ivanka Trump & Topher Grace Cozy Up
11/01/2006 AT 07:30 AM EST
Trump and Grace – who starred as Eric Forman on FOX's That '70s Show and plays the villainous Venom in the upcoming Spider-Man 3 – danced and cuddled on the VIP bed and even shared a quick kiss during the party, which was also attended by Ryan Cabrera, Chelsea Handler and Maroon 5's Adam Levine.
Trump and Grace, 28, who got into the Halloween spirit by wearing a Teen Wolf mask (though he took it off for the kiss), left holding hands.
Is there a romance brewing? Trump's rep did not return calls, and Grace's told PEOPLE, "I don't comment on Topher's personal life."
Before the birthday bash, Trump, Grace and friends – including Grace's That '70s Show costar Wilmer Valderrama – had dinner at the Las Vegas restaurant Social House, and on Friday, they dined with a few other friends at Bellagio's Fix.
Trump, vice president of development and acquisitions for her father Donald's Trump Organization and a regular on his NBC reality show The Apprentice, recently went on "several dates" with Lance Armstrong, but told PEOPLE early this month, "I have tremendous respect for Lance and all he has accomplished. That said, we are just friends."