A magazine report had claimed that Aniston broke up with Theroux after a year-and-a-half of dating, allegedly because he wasn't ready to commit.
But the 43-year-old actress' representative countered, "It's once again just another fabrication to sell magazines and has no relationship to reality."
Among the supposed bits of evidence was Theroux's recent dinner at NYC's ABC Kitchen with a "mystery blonde", reported Us magazine.
In fact, the unidentified woman is actually actress/comedienne Amy Sedaris, an old friend, said a source.
While Aniston shot "We're the Millers" in North Carolina, Theroux enjoyed a group dinner in NYC with some of her closest friends July 30, a second insider said.
The "Wanderlust" actor, 40, dined at Elio's in NYC with Aniston's "Friends" costar Courteney Cox plus Laura Dern.
Cox, 48, brought her daughter Coco, 8, who is Aniston's goddaughter; Dern, 45, brought her son Ellery, 10, and daughter Jaya, 7, to the cosy get-together. "Everyone seemed to be having fun," the source added.
Aniston, meanwhile, is hard at work in North Wilmington, North Carolina on "We're the Millers" with actors Jason Sudeikis and Emma Roberts.
Playing a prostitute in the dark comedy, Aniston was snapped on set last Thursday in tiny Daisy Duke jean shorts and a clingy, white tank top.
