The Cheating Rumors That Plagued Kevin Costner & Christine Baumgartner's Divorce, Explained

In terms of explosive celebrity divorces, the split between actor Kevin Costner and Christine Baumgartner was one for the ages. The couple had an agreement put in place prior to their wedding, but that didn't stop the drama from escalating between the duo as they fought over every issue possible during the end of their marriage.

Costner and Baumgartner began seeing each other in 1998 and got married in 2004. Over their 18-year marriage, the couple welcomed three kids, two sons and a daughter. Unfortunately, the couple couldn't resolve their myriad of issues, and Baumgartner filed for divorce in May 2023, citing "irreconcilable differences" as the reason for their split. The divorce sparked many arguments between Costner and Baumgartner, including who their family home would go to and the problem of child support. The divorce was made even messier when rumors of infidelity from both parties, which both Costner and Baumgartner denied.

Breakups can bring the worst out of a couple, especially when that couple happens to be in the public eye. In the case of Kevin Costner and Christine Baumgartner, social media and online rumors took a toll on their reputations during their divorce proceedings. Shortly after Baumgartner filed for divorce in May 2023, rumors started on social media that the couple was divorcing because Costner had gotten a woman pregnant on the set of his hit show, "Yellowstone." The source of the rumor was unknown, and it was never revealed which woman was allegedly carrying Costner's child. The "Dances with Wolves" actor's representative told The Daily Mail that the rumor was "absolutely not true."

During the divorce proceedings, Costner's lawyers were adamant that he did not commit infidelity during the marriage. According to the court documents (via People), Kevin "does not know for a fact if [Christine] engaged in any 'extramarital romantic relationships' before separation and, if so, whether she spent any of his money or charged any expenses in furtherance of her affair(s) on credit cards he paid." The documents also stated, "[Kevin] has no responsive documents for 'extramarital romantic relationships' in which he engaged because he engaged in none."

As hard as Kevin Costner denied the rumors that he had cheated on ex-wife Christine Baumgartner, the same accusations were thrown her way, too. First, Baumgartner was rumored to have had an affair with Daniel Starr, who was renting the guesthouse on Costner's property. For his part, Starr denied the rumor, telling The Daily Mail in June 2023, "I just had a tenant-landlord relationship [with them], nothing else. There was nothing there. They have kids and are going through a divorce. I just hope that it ends peacefully for them. I hope his divorce resolves and his kids are minimally impacted."

The second accusation of Christine Baumgartner cheating came when she was seen out and about with Josh Connor, a friend of both Baumgartner and Costner's. The pair was spotted on vacation two months after Baumgartner filed for divorce but insisted that nothing romantic happened between them. However, in January 2024, a source close to Baumgartner confirmed that they were dating. The source told People, "Josh was initially just a friend. [She] likes hanging out with him. He is a divorced dad and understands what she's been going through. They both love the ocean and beach life. It's something that makes Christine happy."