Prince Charles and Camilla Parker Bowles
Prince Charles and Camilla Parker Bowles already had an affair while she was still married and even before he met Princess Diana. Pictured: Prince Charles and Camilla during their visit to the Orokonui Ecosanctuary on Nov. 5, 2015 in Dunedin, New Zealand. Getty Images/Rob Jefferies

Prince Charles and Camilla Parker-Bowles never stopped loving each other despite having had relationships with other people. In a new ITV documentary titled "The Real Camilla: HRH the Duchess of Cornwall," more details of the Duke and Duchess' affair were revealed.

According to the clip, Prince Charles and Camilla met in 1970 by chance after a polo match. They started dating soon after, but their romance cooled down when Prince Charles left for naval duties overseas. She did not wait for him and went on and married Andrew Parker-Bowles.

However, Camilla had an unhappy marriage due to her husband's adulterous behavior. As a result, when Prince Charles returned, they rekindled their romance even if she remained married. At the time, the Prince of Wales had not yet met Princess Diana.

"She was unhappy that she was the betrayed woman. This was the real problem," an insider told the program. "That's what sent her back into the arms of Prince Charles."

"Andrew was away an awful lot, and Prince Charles was someone who was kind to her," the insider continued.

Princess Diana was reportedly unaware of Prince Charles and Camilla's romance. In fact, she and Camilla started out as good friends. But when the People's Princess learned about their affair, she changed and became "moody, willful and unpredictable." Princess Diana had also become jealous of whomever Prince Charles spent time with, including Queen Elizabeth II.

In an interview with Panorama in 1995, Princess Diana revealed crucial information about her married life. "There were three of us in this marriage, so it was a bit crowded," she said, when asked if Camilla was a factor in the breakdown of her marital ties with Prince Charles.

In related news, Princess Diana's royal butler also revealed that she suspected Prince Charles of plotting an automobile accident in order to remarry. The late Princess of Wales reportedly already had a premonition of her death.

"Her words were 'these next few months, are the most difficult months of my life. I fear my husband is going to kill me. In an automobile accident. With head injuries. In order that he can remarry,'" Burrell said. "That is spooky. She predicted her own death nine months before she died."

Prince Charles and Camilla's romance did not get the warm support of the Queen at first. In fact, Her Majesty disapproved of their affair and didn't want to see Camilla in any royal function or talk about her. Prince Charles and Camilla eventually won the queen's approval and got married in 2005.