Kevin Costner’s estranged wife Christine breaks down in tears on the witness stand during their child custody hearing

Kevin Costner and his estranged wife appeared in a Santa Barbara, Calif., courtroom Thursday for a disputed child support hearing, and the showdown proved emotional.

Christine Baumgartner took a stand and choked back tears as the questioning turned away Yellowstone Star’s Beach Club property to his sprawling ranch in Aspen, Colorado, where the kids have vacationed many times and think the property is a special place. An eyewitness tells ET that Baumgartner “began to cry and reached for a handkerchief” as this portion of the interview began. There was a 30 second break before the judge ordered a five minute break.

Costner and Baumgartner are in court to resolve their bitter dispute over how much Costner must pay in monthly child support for their three children – sons Cayden, 16, and Hayes, 14, and daughter Grace, 13. The court tentatively ordered Costner to pay her $129,000 per month (He wanted to pay $51,900), and she recently went to court asking for the amount to be increased $175,000 per month (she initially wanted $248,000 per month). Baumgartner filed for divorce in May after 18 years of marriage.

The 68-year-old actor wore a tan suit and black tie and appeared relaxed at the hearing, according to the eyewitness. However, his demeanor changed when Baumgartner’s attorney stated in court that Costner had more than enough money to pay both of her legal bills. a point of contention recently.

“He seemed irritated when Christine’s attorney said he should pay both legal fees,” the eyewitness said. “He visibly shook his head when the attorney said he could afford both.”

The eyewitness went on to say that Costner did not shy away from looking at 49-year-old Baumgartner before she took the stand.

“He sipped his water and looked at her,” the eyewitness said. “He didn’t take his eyes off.”

At the hearing, Baumgartner testified that it was important for the children to have a “comparable lifestyle” that they enjoyed when she and Costner were still a couple, and therefore requested that the court increase the amount Costner paid her should pay monthly child support. She testified that the kids love the beach club’s grounds and that they feel “at home in the water.”

But before the hearing, Costner’s legal team filed new court documents Wednesday afternoon, in which he criticized Baumgartner’s claim that he “steadfastly refuses” to pay enough child support to meet the children’s reasonable needs.

In court documents obtained by ET, Costner called Baumgartner’s claim “provenly false and intentionally inflammatory,” while emphasizing that Costner and Baumgartner “simply disagree on what ‘reasonable needs’ means in the context of child support.” Costner also didn’t mince words when she described her “baseless character attacks” on him.

“Christine’s unrelenting ‘jihad’ against Kevin’s character lends this trial a level of hostility that is wholly unnecessary,” the court documents said.

In the same court documents, Costner claimed Baumgartner had a “boyfriend” — a claim she later refuted — and that the boyfriend “recently gave her $20,000.”

While Baumgartner was on the witness stand at Thursday’s hearing asked about her Hawaii vacation in July with her and Costner’s mutual boyfriend Josh Connor. Baumgartner was asked if Connor was her boyfriend, and she replied, “No.” However, Baumgartner acknowledged that Connor gave her $20,000 as a gift. She was touched on the witness stand and wiped away tears as she revealed she gave half of the money to her mother. When asked why she was emotional, Baumgartner said she was concerned for her mother’s well-being. She also explained that Costner gave her mother $5,000 a month during the marriage, which she says her mother no longer receives.

As for Baumgartner’s claim that the kids are “at home in the water” and therefore need more child support to enable a “comparable lifestyle” to that enjoyed at Costner’s oceanfront beach club property, the The actor states that Baumgartner has already leased a large four-bedroom house in nearby Montecito, just “4 minutes from the beach (5 minutes by bike)”. Costner also revealed that Baumgartner’s Montecito home — a six-month lease for $40,000 — also has a larger pool than the one at his beach club property.

He concluded in his court filings that “the reasonable needs of the children are fully met by a support order of $63,209 per month” and that “amount of child support in excess of that amount is simply spousal support in disguise.” He added, “Christine will have an opportunity to convince the court that she is entitled to spousal support, but that is not the subject of this hearing.”

Costner and Baumgartner have scheduled a second custody hearing for Friday.

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