Mila Kunis is locked in a nasty feud with Leslie Mann, who’s bitter for being left out of her smash hit Bad Moms, RadarOnline.com has learned exclusively!

“Mila is really tired of the backstage drama surrounding 'Bad Moms' and Leslie and her husband Judd Apatow," reveals a source.

As fans know, Mann was originally slated for the lead role but the husband and wife team abruptly dropped out claiming they were too busy to commit to comedy about exhausted mothers battling over-protective parents at their children’s school.

very sore and b***hy about the whole thing and can’t let it go!"

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The other problem looming is Judd "is like a dog who's been kicked too many times," spills the informant, adding the producer "just holds grudges forever and rubs his success in people's faces. And this was a case where he made the wrong bet."

Kunis, however, is a "normal and peaceful person" and doesn't want to make enemies, the insider insists.

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