Kevin Costner Vows to 'Outplay' Estranged Wife Christine Baumgartner in Messy Divorce Battle

Kevin Costner will not be taken down by his split from Christine Baumgartner.

After the Yellowstone star was reportedly blindsided by his wife's decision to officially file for divorce in May after 18 years of marriage, the pair has been entrenched in a bitter legal battle over their shared properties, custody of their children and even the validity of their prenuptial agreement.

"Kevin and his lawyers have made a concerted effort to lower the temperature and stop the tide of bad publicity," an insider said of the actor's longing for the tumultuous situation to be over. "He doesn't want this to be drawn-out."

"Kevin feels betrayed by Christine, but he wants to take the high ground," spilled the source close to Costner, who shares Cayden, 16, Hayes, 14, and Grace, 13, with Baumgartner. "Kevin doesn't want to waste more time fighting with Christine."

Their feud has widely played out in the media, with insiders revealing The Guardian star's dedication to his work over his family was the last straw for the former model. "Their marriage seemed solid and like they were in it for the long term, but the time apart clearly took a toll," a source explained. "Christine just couldn't cope."

Following Baumgartner's swift legal move, she and Costner went head to head in court over their shared assets. As OK! previously reported, the 49-year-old initially refused to leave the former couple's $145 million Santa Barbara mansion despite their pre-martial agreement stating she must vacate within 30 days. After a nasty back and forth between their attorneys, Baumgartner left in July.

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Now, things between Costner and the mother of his children are colder than ever. "They are only speaking through intermediaries," an insider dished. "Kevin would rather use the silent treatment than deal with Christine directly anymore."

"Kevin doesn't hate Christine, but he does want a clean break. Of course, there are resentments and animosity, but that comes with the territory, and he's trying not to make it personal," the source added. "Kevin is a chess player, and he will outplay Christine."

Us Weekly spoke to sources close to Costner.