Cameron on J.Lo: Stick to Your Day Job

Catfight alert: Cameron Diaz is not a fan of Jennifer Lopez, her co-star in the upcoming What to Expect When You’re Expecting. Diaz has been griping about “nightmare” J.Lo’s diva attitude all over the set, and “even said that Jen should stick to her day job, meaning American Idol and singing,” one source tells Now magazine. Particularly irksome: Lopez “demands to eat at specific times, no matter what,” the source says. “So at 10:15am on the dot,” she halts everything to eat a “small protein and veg-based meal. It’s driving Cameron crazy.” (More Cameron Diaz stories.)