Olivia Wilde, Elizabeth Olsen and Charlize Theron Party in NYC

Actresses let their hair down at a Big Apple bash where Olivia spends quality time with a scruffy new guy...does the newly single starlet have a new love interest?

Olivia Wilde turns heads wherever she goes, and last night was no exception.

The freshly single actress was a surprise guest at the HTC Serves Up NYC bash, and she spent most of her time at the party with scruffy director Bryn Mooser (pictured behind her here).

The two were dancing and laughing together, and when they posed for a photo, she kissed him on the cheek. The two even left Highline Studios together with a group at the end of the evening.

So is Olivia off the market already?

Nope. According to a source, Olivia and Bryn are "just great friends." They also work together on the Artists for Peace and Justice charity and produced a documentary together about Haiti called Sun City Picture House.

And how's this for an interesting twist? Bryn used to be engaged to Maria Bello, who was also a producer on the same doc with Olivia and her ex.

Good to see everyone can get along nicely!

Also having a blast at the bash was Elizabeth Olsen, who was dancing while drinking white wine, and Charlize Theron, who arrived after midnight with three security guys in tow.

But she was nice enough to pose for pics with fans as well as with fellow guest Leighton Meester, who was sampling the delicious food whipped up by the famed New York chefs on hand at the fete.