Prince William has been a good son and heir to the throne he once said he would never forgive Princess Diana due to one mistake.

Once Prince Charles takes over the throne, Prince William would spend more of his time serving the Firm even more. Even at a young age, he already knew the responsibilities he has to carry as a future king, and he was aware that people already set their full glares at him.

However, one incident involving Princess Diana caused tensions between them, and it was bad enough for Prince William to think he would never forgive her.

What Happened Between Princess Diana, Prince William?

Among all the broadcasts where Princess Diana appeared, her infamous interview with Martin Bashir where she talked about her marriage to Prince Charles became the root cause of the issues with the Duke of Cambridge.

At that time, she told the disgraced BBC journalist that there were three of them in the marriage - hinting at Prince Charles' infidelity with Camilla.

Royal author Tina Brown recently claimed that the bombshell BBC interview affected Princess Diana's relationship with Prince William.

In her upcoming book, "The Palace Papers: Inside the House of Windsor-The Truth and Turmoil" (via Express UK), she revealed that Prince William was devastated when the Panorama interview was publicized.

"William, who had watched the interview in his Eton housemaster's study, told a classmate that as soon as he saw his mother's face appear on the screen for the interview, he was overcome with a feeling of dread. By the time the housemaster, Andrew Gailey, returned to his study to collect William, he found him, slumped on the sofa, his eyes red with tears," she said.

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The Duke of Cambridge then rushed back to his room. One hour later, Princess Diana reportedly called the house as she wanted to talk to her son, but prince William refused to take the call.

At that time, the Prince of Wales knew he would never forgive her. She then kept asking her psychic, Simone Simmons, what she had done to her children.

Robert Lacey also noted that Prince William was furious that she spoke badly of Prince Charles and that she mentioned Hewitt during the interview. While Princess Diana tried to hug him, Prince William just shoved her away.

The next day, Prince William apologized to her with a bunch of flowers, but Princess Diana still felt that the damage had been done.

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