Jennifer Aniston and Justin Theroux share a cozy dinner

May 19, 2011 at 3:43 p.m. ET

Jennifer Aniston was seen having dinner with actor Justin Theroux. Are the two dating? They've been spotted spending time together lately.

jennifer aniston datingJennifer Aniston may have a new guy. She was seen out on a dinner date with actor Justin Theroux.

Aniston and the actor/writer have been spending time together since March, when the former Friends star was spotted hanging out with the Sex and the City alum at the Chateau Marmont in Los Angeles, California.

The two appear together in an upcoming movie, Wanderlust. The film stars Aniston and Paul Rudd as a couple who flee their upscale existence in New York City for Georgia and end up spending time in a nudist colony.

Last night, Aniston and Theroux arrived separately at the Sunset Tower Hotel, one of Aniston's favorite eating spots, but reportedly they came from Aniston's house and returned there after their meal.

So, was this a dinner among friends or something more romantic?

"They are great friends," a source says. "When Justin is in L.A. from New York, he and Jen have spent a lot of time together lately."

As for Wednesday evening, the source said, "Jen was in a great mood and seemed happy to take Justin to her favorite restaurant... They seemed happy and were flirty, but didn't act like a couple."

Of course, with the whole world watching, they may be taking pains to appear like they are "just friends."

Theroux is based in New York and tends to play quirky characters in independent films. He co-wrote Tropic Thunder and wrote the screenplay for Iron Man 2. You might also remember him as the neurotic guy Carrie Bradshaw dated in an episode of Sex and the City where Carrie liked her date's mother better than her date.