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For Jennifer Aniston, timing is everything. One day after Us Weekly claimed that she felt "rejected and upset" that Bradley Cooper had opted for the company of Renée Zellweger, she was purportedly spied sharing another cozy moment with her "Bounty" co-star Gerard Butler, whom she was linked to last month.

RELATED: See more photos of Jen and that fabulous head of hair says the pair appeared quite friendly between takes as they filmed a fight scene in New York on Wednesday.

"We saw him give her a little kiss," alleges an on-set source. "They were very lovey-dovey."

According to the mole, Aniston, 40, and Butler, 39, have been "flirty and affectionate" off-camera and have a habit of hanging out in her trailer.

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"We watched them at one point start to hold hands, but she pulled back because she realized people were watching," maintains the snitch, who then takes a body language leap by concluding, "They look like they're in the beginning phase of a relationship that's really nice."

Or, you know, not. Aniston's rep tells Gossip Cop that the story isn't true, with a Butler buddy adding that he's "definitely dating up a storm but nobody special."

Either way, the stars seem to be having a good time together. Not only was Aniston still smiling after a scene in which Butler dumped her into the trunk of a car, but she's also evidently willing to put her flawless figure at risk by ingesting salty snacks with him.

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"Jen and Gerard were joking around [on Thursday] and he started to feed her popcorn and peanuts," relays the spy. "He was popping them in her mouth and she was laughing while eating."

Butler has repeatedly dismissed reports that he's dating Aniston, telling GMTV a few weeks back, "If I was, I would say I was. It's just that if you're not married in Hollywood and you're working with somebody else who's single, you're having a thing with her."

Still, suave guy that he is, he's managed to put a complimentary spin on his romantic denials.

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"She is one classy lady," he told People magazine last month of the actress. "Every day I go to work with her I'm always surprised about how cool, easy and down-to-earth and real she is."

Aniston, for her part, apparently doesn't consider Butler boyfriend material, with a confidant telling the mag last month, "They get along really well, but Jen only likes him as a friend. She can't see herself dating him."

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