(Cover) - EN Showbiz - Justin Theroux thinks Jennifer Aniston is "fantastic".

The 39-year-old actor starred alongside Jennifer while filming the comedy Wanderlust last year, and now the two are reportedly dating.

The American star gushed about working with the Hollywood beauty, insisting Jennifer was the most impressive co-star he's ever worked with.

"She was fantastic, the classiest lady I know," he revealed in a recent interview with Life & Style.

Justin has recently split with his long term girlfriend, stylist Heidi Bivens and has recently has been getting to know Jennifer on a series of low-key dates in Los Angeles.

Sources close to the star have revealed that Justin has always had a soft spot for Jennifer, who is widely considered one of Hollywood's most beautiful women. Friends of Justin have admitted that he was wowed by her physical presence after meeting her on the set of Wanderlust.

"Justin has always had a thing for Jennifer," a friend has revealed. "He thinks she's very sexy, and when he spent time with her on Wanderlust, he thought she was even hotter in person. He was infatuated with her the whole time during filming."

Justin has become more open about his feelings since meeting Jennifer. His close friend has revealed that the star is totally smitten by the stunning actress.

"I have never seen Justin this way with a girl before. He was always so quiet and private about Heidi. He never raved about her. But with Jennifer, Justin can't say enough good things," the source added.

Last month, it was reported Jennifer had found a new boyfriend who is a "homebody" and the pair have been enjoying low-key dates watching television and sharing a bottle of wine. (C) Cover Media