Jennifer vs. Jennifer: It’s On!

Hugh Hefner’s bleach-blond harem-scare ‘em isn’t the only catfight in town.

Life & Style reports that Jennifer Aniston bumped her He’s Just Not That into You costar Jennifer Connelly from an upcoming photo shoot for Marie Claire magazine.

Just in case Connelly misses Aniston’s point, the comedy’s other stars, Drew Barrymore and Ginnifer Goodwin, will be gracing the cover along with Aniston. Ouch!

“There was no camaraderie between those two whatsoever,” says an insider. “Word is, Aniston threatened to pull out if Jennifer was part of the cover.”

As for what might have led to the chilly relationship between the two Jens, no one’s saying.

Maybe it’s because Connelly keeps leaving Jessica Simpson’s “Come on Over” playing on the voice mail of John Mayer’s newest conquest.