Another week, another celebrity's marriage in pieces.

TMZ reports that Dennis Quaid's third wife, Kimberly Buffington-Quaid, has filed for legal separation, though sources told the website that the separation is just a formality due to California residency laws, and divorce papers will be filed in the coming months.

The separation isn't completely unexpected given that Kimberly filed for divorce in March, but decided to give the marriage another chance when she withdrew her petition in May.

The reconciliation didn't last long, and a source told TMZ that Quaid's wife is "fed up with Dennis' cheating and wants out of the marriage," and added that the actor is "not a good husband."

The couple married on July 4, 2004, at an intimate ceremony on his 500-acre Montana Ranch. According to the separation documents obtained by TMZ, Kimberly is asking for joint legal and sole physical custody of the couple's 4-year-old twins, Thomas Boone and Zoe Grace.

This will be Quaid's third divorce; he was previously married to actress P.J. Soles (1978-1983) and Meg Ryan (1991-2001), with whom he has one child.

The 58-year-old actor recently spoke to Parade about the difficulty of celebrity marriages:

"It’s hard for two actors to be together. Take the traveling, for instance. It winds up being a long distance relationship, all the time, because one’s working here and one’s working there, or one’s staying at home and one’s off someplace else. Your partner has to live with the best and the worst part of you, and they’re affected by it," he said.

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    They called it quits again.

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  • Lauren Conrad & Kyle Howard

  • Jessica Biel & Justin Timberlake

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  • Christina Aguilera & Jordan Bratman

  • Ashlee Simpson & Pete Wentz

  • Maria Shriver & Arnold Schwarzenegger

  • Tom Cruise and Katie Holmes

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  • Heidi Klum and Seal

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  • Will Arnett and Amy Poehler

  • Maria Sharapova and Sasha Vujacic

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  • Chris Harrison and Gwen Harrison

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  • Dennis and Kimberly Quaid

  • Debra Messing and Daniel Zelman

  • Michaele and Tareq Salahi

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