The Two and a Half Men star was photographed with three women on early Tuesday morning (December 20), one of which was a lookalike for Kutcher's estranged wife Demi Moore, according to Us Weekly.
"[Kutcher and the Demi Moore lookalike] sat at the open window, talking, flirting, drinking red wine and smoking one cig after another," a witness told the website.
The source went on to say that Kutcher "left the party with three girls in tow, including the Demi Moore lookalike".
Moore filed for divorce from Kutcher in November amid allegations that he had been unfaithful with 23-year-old Sara Leal.
The actress recently insisted that she is in no hurry to change her Twitter handle Mrskutcher, adding that she doesn't owe anybody an explanation for her reluctance to change the name.