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Often times the best movies are the ones that come from personal experiences, and that's just what Billy Crystal mined for his new comedy with Bette Midler, Parental Guidance. Get a first look behind the scenes!

Video: Watch the 'Parental Guidance' Trailer 

Inspired by his own real-life experience of being asked to babysit his daughter's kids for several days, Billy says he immediately cranked out a story after all the mishaps and misunderstandings he endured: "It became a real contemporary story about old school vs. new school, about how I as a parent parented, and how my daughter is parenting now -- and our conflicts about doing that."

In theaters Christmas Day, Parental Guidance casts Billy as Artie, a grandfather who's used to calling the shots. When his eager-to-please wife Diane (played by Bette) agrees to babysit their three grandkids -- much to Artie's chagrin -- modern problems collide with Artie and Diane's old school methods of tough rules. But despite the numerous problems that come up -- yielding hilarious comedic dividends -- the family ultimately learns that they can come together by embracing the best of both worlds. Marisa Tomei and Tom Everett Scott also play the kids' type-A helicopter parents.

Video: Helen Mirren & Billy Crystal Vamp Up 'When Harry Met Sally 2'

"It's a human story told in a very funny and sweet way," says Bette. "I think everybody's in this film -- we've all clashed with our parents … we've all been treated well or badly, we all have vulnerabilities, we've all tried really, really hard to accomplish something and either succeeded or failed at it. It's a human experience."