Princess Diana broke down in tears after she sent off her ex-husband, Prince Charles, on his five-week tour of Australia. And a photo of the late royal shows how sad she really was.

In the snap, the Princess of Wales is wearing a red jacket and she is staring at Prince Charles while he is walking farther away from her. She has tears in her eyes, and she’s trying to breathe from her mouth.

Prince Charles’ five-week trip to Australia was the first time that Princess Diana was separated from Prince Charles shortly after their engagement. As such, the mom of two didn’t know what to do about the distance.

But what probably made Princess Diana, even more, was the fact that Prince Charles was so used to traveling overseas that he didn’t seem to mind being away from his future wife. While Princess Diana’s photos and television clips show her crying, Prince Charles looked stoic.

In the book “Charles: A Biography” royal author Anthony Holden sheds more light on what happened between the royal couple behind closed doors. He said that there was another reason why Princess Diana was weeping when she stepped out in public.

After arriving at the palace to send her then-boyfriend off, Prince Charles received a phone call from the love of his life, Camilla Parker Bowles. The Duke and Duchess of Cornwall chatted on the phone for a few minutes, and Princess Diana felt that her short time with her future husband was taken away by Camilla.

Princess Diana eventually decided to leave Prince Charles alone so that he could have some privacy while talking to Camilla. And 10 years after the incident, Prince William and Prince Harry’s mom said that the incident broke her heart.

But despite the heartbreak that she experienced, Princess Diana and Prince Charles still pushed through with their wedding. Unfortunately, things didn’t work out and they divorced.

Princess Diana and Prince Charles
Princess Diana and Prince Charles at the Chelsea Flower Show, London, May 1984. She is wearing a navy maternity coat by Jan van Velden. Getty Images/Jayne Fincher