Earl Charles Spencer’s third wife, Karen, has accused him of having a ‘long-term mistress’ and ending their 13-year marriage by text message.

According to court documents obtained by People , Karen Spencer claims that her ex-husband has been having an affair since 2022 and “most likely since 2021” with Dr. Cat Jarman – his current girlfriend. This series of shocking statements is part of Karen’s defense in Jarman’s lawsuit against Countess Spencer for misuse of personal information.

Countess Karen Spencer is the third wife of Princess Diana’s younger brother. Photo: UK Press

In the lawsuit filed in October 2024, Cat, 42, accused Karen, 52, of spreading private information about her multiple sclerosis diagnosis, despite her desire to keep it private. However, Karen argued that it was “reasonable” for her to discuss Cat’s information because she had discovered the archaeologist’s relationship with Earl Spencer.

“Ms. Spencer shared the information in question with her family, close friends and associates. She did so in a completely reasonable and legal manner, as part of her handling and accepting her husband’s sudden and cruel request for divorce,” Karen’s filing reads.

“In addition, under those circumstances, Cat did not provide any reasonable reason why Ms. Spencer should not discuss this information with the small group to whom she confided,” People further quoted the filing.

Earl Charles Spencer and his current girlfriend, archaeologist Cat Jarman. Photo: Instagram

In the documents, Karen also accused Charles Spencer of “informing her that their marriage was over” on March 19, 2024, by text message. The 52-year-old countess said Princess Diana’s brother’s behavior was “inconsiderate and deliberately provocative”.

“The fact that he ultimately chose to end their marriage by text message, completely refusing to have any direct conversation with her or offer any explanation, despite her repeated requests in the weeks that followed, is both cruel and incomprehensible,” the document continued.

Karen claims she discovered her husband’s affair with Cat after contacting Cat’s husband, Tom Jarman. During a Zoom call in April, Karen asked Tom “do you suspect they’re having an affair?” and he replied “yes”.

After comparing the timelines, Karen and Tom realized that their spouses’ affair could have been going on since at least November or December 2022, when Charles Spencer and Cat were both in Norfolk. It is even more likely that the two had been “in love” since 2021.

Earl Spencer and his third wife attend Harry and Meghan’s wedding in 2018. Photo: UK Press

Shocked and heartbroken by the discovery, Karen chose to confront Cat – who was said to be staying at “a house a few hundred metres from the Spencers’ Althorp residence” and regularly came for meals. In an email to Cat included in court documents, Karen said Cat was not welcome at the house while she was still living there with her daughter, Charlotte Diana.

“I have to keep that boundary. It’s not fair to me, our daughter, or all the servants who were surprised by the news of our divorce and still have to serve Charles. It’s too cruel,” Karen wrote in an email.

The 52-year-old countess also said she felt disappointed with Cat for breaking up her family. “First of all, as a woman, I have to tell you that I am very disappointed in you. It is so unethical to disrupt a child’s life like this,” Karen added.

Karen believes Cat and Charles Spencer “bullied” her by filing the lawsuit. Karen insists that it was “completely understandable” that she told the story about Cat to a small group of people close to her because of “his relevance to the case”.

Earl Spencer hugs his new lover on the streets of London in June 2024. Photo: Backgrid

However, according to the Mail , Prince William ‘s uncle and archaeologist Cat Jarman now deny the affair allegations, insisting they did nothing wrong. The 9th Earl Spencer called his ex-wife’s allegations a “ridiculous attempt to tarnish his reputation” and denied that he had sent a text message to break up.

Meanwhile, Cat accuses Countess Spencer of fabricating the story to launch “a vile, defamatory attack” on her and Charles Spencer.

“I am shocked and utterly disappointed that my legitimate efforts to prevent the unlawful public disclosure that I have multiple sclerosis – a protected disability – have been dismissed in such a horrendous and deceitful manner,” the archaeologist said.

Earl Spencer announced his divorce from Karen in June 2024. Just days later, he was spotted going to the opera with the 42-year-old doctor. But it was four months later, in a magazine interview, that Charles Spencer confirmed Cat as his new girlfriend.

Charles Spencer and Karen married on 18 June 2011 in Althorp, where the Earl and his sister Diana grew up. They have a 12-year-old daughter, Charlotte Diana. Karen has two children with her ex-husband, Hollywood film producer Mark Gordon. Spencer has four children with his first wife Victoria Lockwood and two with his second wife Caroline Freud.