The Anchorman: The Legend of Ron Burgundy star, who usually plays good girls onscreen, switched things up for her latest film as uptight Parent Teacher Association head Bee Gwendolyn - and she admits didn't feel comfortable being rude to co-stars like Mila Kunis and Kristen Bell, who were cast as less-than-perfect parents in the movie.

"Sometimes I feel really icky inside after a scene...," Christina confessed to U.S. breakfast show Today. "I wanted to apologise to the person I'm working with, because it feels real dirty (sic)."

The movie's plot pits Christina, Jada Pinkett Smith, and Annie Mumolo's characters against those played by Mila, Kristen, and Kathryn Hahn, and new mum Kunis admits she had a ball with her fellow leading ladies on set.

"It is the greatest group of women I have ever worked with in my life," the Jupiter Ascending star gushed, revealing they all bonded over their real-life struggles as working mums.

"You come into the trailer (in between shoots) and everyone's Skyping (sic) with their kids," the mother-of-one recalled. "Every day you hear, 'Did you do your homework?' or 'What are you eating?' Everybody's constantly checking (in on their families). It's the greatest environment to be in."

And working on Bad Moms only proved to Christina, who is mother to five-year-old daughter Sadie, that trying to be a perfect parent was unrealistic.

"All we can do is our very, very best, and we're gonna fail and that's how you get up and that's how you learn," she mused. "We're all just trying and it's OK to say, 'Yeah, you know what? I was a really crappy mum today but you know what? My kid's alive and fed...'"

Chiming in, mum-of-three Jada added: "And there's always tomorrow!"