Whether it's true or whether it isn't, Spencer bringing it up now, almost THIRTY YEARS later, when the King is elderly and clearly has terminal cancer, is just despicable. And it's very possible that he misheard or misinterpreted what the king said. Charles seems like an old romantic softie to me, having only loved one woman his whole life, and it speaks well of him that she's not someone of great beauty who's much younger than him. He clearly goes for personality. He is adamant that he did not go back to Camilla until five years later, after the marriage had irretrievably broken down.
And Diana must have been very, very difficult to live with. She very clearly suffered from a Cluster B disorder, and those are the histrionic ones. In Sally Bedell's book, she related how Diana would whack Charles around the head when he was praying before bed, and she has it on good authority that Diana slept with someone else first. Only then did he go back to Camilla.
I do not think that KC is a cruel man at all, but I do believe that Diana drove him to the edge. I was married to a Cluster B, and they are like deep, dark tar pits who suck you in and won't let go. Woe betide their spouse, because they tend to save it all for them. Diana's mental-health problems were not her fault, but I can imagine they affected Charles profoundly, especially being trapped like he was.
The Spencers really are awful people. Diana recounts in her tapes how she saw her father smack her mother in the face. Diana's paternal grandfather would hit his wife, too. The current earl has had more divorces than he's had hot dinners, at least two of his wives said he had multiple affairs, and his latest ex-wife said in court papers how much he'd bullied her. Diana had no problem using violence on people when she wanted to. She slapped her father in the face when he told her he was marrying Raine, and she pushed Raine down a flight of stairs, leaving her badly bruised. Falling downstairs can easily kill someone. Before her marriage, a man stood her up for a date, and she covered his car with egg and flour, which is famously damaging for car paint and really hard to get off once it's set. In addition, after she split from Charles, 600 calls were made to the married Oliver Hoare, and they were all traced back to Kensington Palace. Will Carling's wife, Julia Carling, cited Diana as the reason their marriage broke down.
And then we have Harry and his callous treatment of his family. And now Charles Spencer's treatment of King Charles.
The Spencers are a bad lot. King Charles's only mistake was marrying the wrong woman. As Prince of Wales, he could have been a total player, but he only ever wanted Camilla, and there are so many reputable reports that he only went back to her once Diana had driven him to the brink of utter despair, around five years in. I think he's a much better person than Spencer. Even if, under extreme stress and shock, Charles did say that, it was so long ago and I'm sure he regretted it. If it's true.
Regardless, I think Earl Spencer is a nasty, vindictive, spiteful man of bad character. Just like his royal nephew.