Prince William was reportedly furious with his mom, Princess Diana, over one of her interviews.

In Amazon Prime's documentary titled "William and Harry: Brothers in Arms," royal correspondent Katie Nicholl revealed how the Duke of Cambridge reacted to one of Princess Diana's shocking interviews. "William was exposed to everything from the interview and called his mother in a fury and a rage," Nicholl said (as quoted by Express).

Recalling a conversation with Princess Diana's close friend Simone Simmons, the Vanity Fair correspondent added: "[She told me] it was the one time William turned on his mother and said, that he would never forgive Diana for what she’d done."

Prince William didn't like when the late Princess of Wales revealed that her marriage with Prince Charles was difficult as there were three of them in their marriage implying about Prince Charles' affair with Camilla Parker Bowles.

After two decades from Princess Diana's death, Prince William opened up about the shocking admission in BBC documentary "Diana, 7 Days." He confessed that he understood his mom for speaking up in public.

"I can understand – having sometimes been in those situations, you feel incredibly desperate and it is very unfair that things are being said that are untrue," Prince William said.

"The easiest thing to do is just to say or go to the media yourself. Open that door. [But] once you’ve opened it you can never close it again."

Although Prince William felt bad about the said interview, he had great times with his mom, Princess Diana and younger brother, Prince Harry. According to Paul Burrell, the trio would spend their Saturday nights eating McDonald's while watching blind date.

Also, following Princess Diana and Prince Charles' divorce, the People's Princess was stripped of her royal title. In fact, she had to curtsy to her own sons, but the Duke of Cambridge comforted his own mom and promised to give it back to her.

"Don't worry Mummy, I will give it back to you one day when I am king," Prince William said.