Princess Diana nearly canceled her wedding to King Charles — then her father stepped in: biographer

Talk about a royal pain in the neck.

Royal biographer Ingrid Seward claimed in her upcoming book “My Mother And I” that Princess Diana almost called off her wedding to the then-Prince Charles after the heir-apparent failed to pay her enough attention.

“With just over a month to go until she married the heir to the throne, Lady Diana Spencer was looking forward to dancing with her fiance,” Seward, 76, wrote in an excerpt featured in the Daily Mail. “Along with the entire Royal Family, she’d been invited to a party at Windsor Castle to celebrate Prince Andrew’s 21st birthday.”

According to the biographer, Diana was hoping to get a chance to dance with her soon-to-be husband but the prince “spent the entire evening dutifully working the room and making sure he spoke with as many people as possible.”

“Diana was in despair,” Seward wrote. “Her fiancé had been away in America for most of the previous week, yet he clearly had no desire to dance with her.”

“Feeling emotionally drained, she threw herself into dancing frantically with one man after another — and finally just dancing by herself,” she said noting that one footman — named Mark Simpson — later saw the princess “looking exhausted and lost in her thoughts yet still moving in slow, rhythmic time to some tune in her head” while roaming the castle quadrangle.

The author noted that Diana later arrived at her father’s home in the early hours of the following morning feeling “distraught, flustered, angry and had no intention of ever going back.”

Seward claims that upon telling her father, Earl Spencer, of her decision, the patriarch was “appalled.”

 “After calming her down, he pointed out it would be an act of gross discourtesy to break off her engagement to the future King so close to the wedding,” Seward writes. “And, anyway, wasn’t it what she’d always wanted? Didn’t she remember him telling her that she should only marry a man she loved – and her firm reply: ‘That is what I am doing’? Diana wasn’t immediately convinced”

Eventually, Seward claims that the elder Spencer was able to convince his daughter to go through with the wedding.

“She couldn’t deny that she still wanted to be the Princess of Wales. And, at 19, she was young enough still to believe in happy endings, despite what her instincts had told her on that terrible night,” Seward wrote.

Charles, 75, would later go on to marry Diana in July 1981 and the two would remain married through 1996 when the pair announced that they would officially be splitting.

Diana would go on to seemingly date the Egyptian filmmaker Dodi Fayed before their sudden deaths in 1997.

Charles would later reunite with his long-time love Camilla Parker-Bowles, whom he would marry in 2002.

The book, which is set to hit bookshelves on Feb. 15, also delves into the relationship between Diana and the late Queen Elizabeth II.

“She wondered whether anyone that young could differentiate between the man and the prince,” Seward wrote regarding the reservations the late monarch had of Diana. “And she couldn’t help thinking that the Spencer girl would be far better suited to her younger son, Andrew.”