Jennifer Aniston, Justin Theroux Rock Matching Rings

Are Jennifer Aniston and Justin Theroux's matching rings a sign they're serious?

June 21, 2011 — -- They may not be wedding bands, but the matching jewelry Jennifer Aniston and Justin Theroux are sporting could be a sign that their relationship is heading in that direction.

Aniston has been spotted multiple times wearing a chunky gold ring similar to one Theroux has been rocking for months. She flashed it at Spike TV's "Guy's Choice" awards on June 4 and recently wore it while out and about in New York.

Theroux wore his at the premiere of his latest film, "Your Highness," in April. He's also been photographed on the town with the ring on his finger.

The new couple seems to be going strong after allegations last week that Aniston broke up Theroux's long-term relationship with girlfriend Heidi Bivens. The two had reportedly been together for 14 years; she recently moved out of his home.

Aniston threw a small get-together May 27 to introduce Theroux to her best pals, Chelsea Handler and Courteney Cox, putting to bed rumors that she and Cox were on the outs after Cox's separation from David Arquette.

Cox apparently approved of Aniston's new beau.

"They all had a great time and enjoyed Justin's company," a source told People magazine.

Aniston, 42, and Theroux, 39, first became friendly on the set of "Wanderlust" in the fall, according People. Aniston has been known to fall for her co-stars. (Remember Vince Vaughn and Gerard Butler?)

But Theroux is different. For one thing, he doesn't have those dashing leading-man looks. He's darker and scruffier and more likely to be cast as the villain: He was Drew Barrymore's evil ex in "Charlie's Angels Full Throttle" and the evil wizard Leezar in this year's "Your Highness."

He can play drama or comedy, big or small screen, and he has serious writing cred. He co-wrote the comedy hit "Tropic Thunder" and, on the recommendation of star Robert Downey Jr., wrote the screenplay for "Iron Man 2."

If Aniston seems to be departing from her own script in her personal life, she's certainly doing the same professionally.

In her new movie, "Horrible Bosses," the queen of romantic comedies sheds her girl-next-door image to play a "sexually aggressive" dentist who harasses her male assistant, played by Charlie Day.

Aniston reportedly has filmed one topless scene, a first for her at age 42. But whether the scene will remain in the film when it's released July 8 has yet to be decided.