Cameron Diaz Jennifer Lopez Feud On Set Of “What To Expect…”

There’s only room for one diva on the set of the upcoming comedy What to Expect When You’re Expecting. Do you feel an icy breeze? It’s gusting from the set — where things are unexpectedly frosty between co-stars Jennifer Lopez and Cameron Diaz.

The girls are in Atlanta shooting the film adaptation of the hit pregnancy guidebook, but we hear the real drama is unfolding behind the scenes. According to reports, the two actresses pretty much, err, hate each other.

Wonder why we’re not surprised.

“Jennifer and Cameron don’t like each other at all,” an on-set source reveals in this week’s edition of Star Magazine. “They don’t interact much, but when they do, the tension is thick.”

Cameron, 38, is reportedly appalled by J.Lo’s diva-like behavior on set, and has been badmouthing the American Idol judge behind her back for having a “huge entourage,” which includes her mom, three assistants, a hair and makeup team, and her manager.

“She made a snide comment to the effect of ‘how many people does it take for one woman to film a simple scene?'” an insider reveals.

Another snoop tells the mag: “They don’t interact much, but when they do, the tension is thick.”

And it doesn’t even stop there.

Cammy even clawed at Jennifer’s acting ability too!

“She said…she’d be better sticking to her day jobs- meaning singing and judging Idol…” said the source.

Meanwhile, J.Lo’s got better things to worry about.

“She just acts as if Cam doesn’t exist.”