It's no secret that Prince Charles and Princess Diana were never as perfect a match as they initially seemed, but a new claim that Charles was "desperate" to back out of the 1981 royal wedding makes the marriage seem like an especially bad idea in hindsight.

In a new unauthorized biography, Charles: Heart Of A King, author Catherine Mayer writes that Charles wanted to call off marrying Lady Diana Spencer.

According to The Telegraph, Mayer -- who interviewed members of the Prince's inner circle -- details a moment on the night before his wedding when a "desperate" Charles reportedly told an aide, "I can't go through with it ... I can't do it."

He is also said to have confessed Diana was "not the jolly country girl he had assumed."

Charles wasn't alone in his doubts about the relationship. In a famous account from the 1992 book Diana: Her True Story, for which the Princess of Wales covertly cooperated with author Andrew Morton, Diana told her sisters just days before the wedding that she didn't think she could marry Charles because he was still carrying a torch for Camilla Parker Bowles.

"...I went upstairs, had lunch with my sisters who were there and said: 'I can't marry him, I can't do this, this is absolutely unbelievable.' They were wonderful and said: 'Well, bad luck, Duch, your face is on the tea towels so you're too late to chicken out.' So we made light of it."

Later revelations aside, the pair shared an awkward pre-wedding interview in which they couldn't have looked more uncomfortable when asked about their engagement.

"I had a long time to think about it, because I knew the pressure was on both of us. And, um ... it wasn't a difficult decision in the end. It's what I wanted," Diana said, adding quickly, "It's what I want."

Asked if they were in love, Charles followed up Diana's quick "of course" with the infamous line: "Whatever love means."

Spoiler alert: The couple divorced 14 years later.

H/T The Daily Beast