Jen Aniston, Justin Theroux Pack on PDA in Photos

Credit: Jordan Strauss/WireImage

It's been a long time since Jennifer Aniston looked this in love.

In two new black-and-white images posted Wednesday by photographer Terry Richardson, the Horrible Bosses actress, 42, and new beau Justin Theroux, put their love on display during a recent trip to New York City. (See the photos here.)

In one shot, Aniston nuzzles 39-year-old Theroux's neck while out on Thompson Street in the city's SoHo neighborhood. The other image features the lovey-dovey couple after they shared dinner with Richardson, 45.

Several insiders tell the new issue of Us Weekly (out now) that Aniston was determined to forge a relationship with her Wanderlust costar, despite Theroux's 14-year relationship with live-in girlfriend Heidi Bivens.

"Jen went after him," a set source tells Us. As Wanderlust's shoot continued, the two began having secret trysts at Aniston's temporary digs, a huge, secluded house on Georgia's Lake Rabun.

"Jen wanted Justin and it didn't matter that he was already with someone," a Theroux insider says.

Bivens, 35 -- who was abruptly dumped by Theroux in March 2011 -- "didn't know Aniston was the catalyst" behind the split, a source says, "until now."

For more details on Aniston and Theroux's shocking new romance -- including  how Bivens thinks it's "tacky," how Theroux is "obsessed" with becoming a superstar, and more -- pick up the new Us Weekly, out now!