Prince Charles wanted a girl when Princess Diana delivered Prince Harry, and this reportedly triggered their shaky marriage.

When the People's Princess gave birth to her second son, she was overjoyed. Prince Harry got red hair, a trait that runs in her family. Princess Diana described Prince Harry as a "miracle" and "a complete joy" to her life, but Prince Charles apparently didn't feel the same.

In Andrew Morton's biography "Diana: Her True  Story," the Princess of Wales revealed that she was hurt by Prince Charles' comments after seeing Prince Harry. "Oh God, it's a boy," the Prince of Wales said (via Express).

The next heir insisted that he was only joking with his reaction. However, he had already hurt Princess Diana with his remarks because apparently, he wanted a girl for their second child. Meanwhile, Princess Diana had known that they were expecting another boy after Prince William because she saw the scan, but she kept it secret from Prince Charles because he has a gender preference for their baby.

Prince Charles reportedly complained to Princess Diana's mom, telling her that he was "so disappointed - we thought it would be a girl." Frances Shand Kydd just told the prince that he was still lucky because his newborn was normal.

Prince Charles' remarks hurt Princess Diana. The Princess of Wales told Morton that after the incident "something inside me closed off" and their marriage broke down shortly that resulted in divorce.

Aside from this issue, Princess Diana said earlier that their marriage was difficult as there were three of them. She knew Prince Charles affair with Camilla Parker Bowles and even confronted her once about their relationship.

Camilla had done a lot of things in the past that extremely hurt Prince William and Prince Harry's mom. According to Princess Diana, she was brokenhearted when Prince Charles was about to leave for his five-week royal tour months before their wedding and Camilla called. But, she chose to be nice and left the two talking on the phone.

Camilla also ruined their honeymoon by sending a gift to Prince Charles. Princess Diana confessed that she confronted Prince Charles about the cufflinks, but he dismissed her concern by telling Princess Diana that it was a present from a friend.