Princess Diana confided in her longtime dance teacher as her marriage to Charles fell apart.

In 1986, in the middle of a ballet class with her longtime teacher, a willowy Princess Diana sat on the floor, tears welling in her eyes.

“I just can’t seem to do anything right when it comes to my husband. I do love him so much and want him to be proud of me, but I don’t think he feels the same way,” she said, according to Anne Allan, the author of the new memoir, “Dancing with Diana,” out Tuesday. “I don’t understand why I am not enough for him; I think he prefers an older woman … I know he is seeing Camilla again.”

Diana started taking dance lessons with Allan just weeks after her fairytale wedding to Prince Charles at St. Paul’s Cathedral on July 29, 1981.

Diana rehearsed in private for her top-secret performance with Wayne Sleep at the Royal Opera House in December 1985.Reg Wilson/REX/Shutterstock

The princess and Allan, a London City Ballet dancer, became close friends, with Di confiding in her over the years as she grew increasingly unhappy in her marriage.

The emotional moment in 1986 was the first time that Allan had ever heard of Camilla Parker-Bowles.

“Why does he not love me? I really don’t understand. I have tried everything, tried to conform to his wishes even though I don’t always agree,” Diana said.

“There’s no affection between us, and I am always on my own. I just want to be loved. I can’t keep going on like this. They are really expecting me to just say nothing and keep going. How do I do that?”

Charles was not happy about his wife’s love of dance. Allan saw this firsthand in December 1985 after she helped Diana rehearse with their mutual friend, ballet dancer Wayne Sleep, for a surprise performance at the Royal Opera House.

Former London City Ballet dancer and ballet mistress Anne Allan gave Diana private lessons for seven years.David Leyes

The 5-foot-11 princess joined Sleep, who is just 5-foot-2, to dance to Billy Joel’s “Uptown Girl,” chosen specifically by Diana.

After coming off stage, Diana laughed and exclaimed, “Beats the wedding!” according to Allan.

“She made her way to Charles, and as she stood before him, I could sense she desperately wanted his approval. He said, ‘Well done, darling’, and turned to talk with someone else. I sensed disapproval from him and my heart took a thud,” Allan writes.

Diana often wrote to Allan and invited her to Buckingham Palace and Kensington Palace.dancingwithdianabook/Instagram

Although other guests praised Diana, Allan recalls, “I was acutely conscious of those from the royal circle who did not say anything to her and looked down their nose at me, their disapproval evident.”

Still, Diana told her she would never forget the evening.

At their next lesson, “with a bit of a naughty grin on her face” Diana admitted that Charles “had not liked her showing herself in that way.”

Ballet dancer Wayne Sleep performed a routine to “Uptown Girl” with Diana.News Group/Shutterstock

Sleep was 5-foot-2, compared to Diana’s 5-foot-11.News Group/Shutterstock

The performance had been kept secret for months, but Allan says Prince Charles was less than thrilled.News Group/Shutterstock

Things got worse.

In 1987, Diana was left bereft by the death of her police bodyguard and reported lover Barry Mannakee in a motorbike accident.

Diana would later describe Mannakee as her “the greatest love” in tapes recorded by her voice coach, Peter Settelen,

Soon after Mannakee’s death, Diana told Allen that Charles wanted to live separate lives, admitting, “All I want is to be with Charles and be loved by him, there’s just emptiness just now … he runs off to Camilla whenever he can. It’s not at all what I want. I’d like the marriage to work, but it just isn’t for now. Do I just put up with it, hoping he will change?”

By the time the Prince and Princess of Wales toured Australia in 1988, their marriage had broken down.Brendan Beirne/Shutterstock

When Allan asked if she could live without love and sex, Diana “blushed” and said she had met someone who made her feel “much better about herself.”

It was later revealed that she had embarked on an affair with Maj. James Hewitt in 1986.

“It made me happy to know that someone was caring for her in an affectionate, loving way, even though I was concerned that it might cause her hurt if it became known,” Allan writes.

Diana hit the headlines when she danced with John Travolta at the White House in November 1985.Reuters Photographer

As Diana’s marriage disintegrated, she once again “dropped” to the floor sobbing, Allan remembers, and said she was in an “unbearable situation,” having not seen her husband in weeks.

“Diana wanted Charles to be with her and to love her. Even though she was in her own romantic affair, at this point, Charles was still the man she desired and that was why it was so agonizing for her.”

After this, Diana’s Lady-in-Waiting, Anne Beckwith-Smith, called to say the princess may want to stop her lessons, but when Allan asked Diana, she was “annoyed”, making it clear it was the Palace who wanted to end things.

Travolta famously twirled Diana around the dance floor.AP

Soon afterward, Diana said that she was “ashamed” to admit she was suffering from bulimia.

Allan had feared as much after Diana fainted during a trip to Vancouver in 1987.

“I gathered that the Palace had concerns and were aware, or at least suspected the problem,” she writes. “I realized that they may have been worried that it could be dangerous if anyone from the outside world found out … The more I thought, the angrier I felt. If the ‘establishment’ knew definitively, had anyone reached out to offer help and guidance? It didn’t seem that they had. Had they dismissed this disease as a sign of weakness, not understanding the mental anguish Diana was in?”

Diana’s bulimia was exacerbated by her marriage woes, leaving Allan “angry” at the future king’s affair with Camilla.

Diana wept as she revealed her marriage issues to her dance teacher.Getty Images

“Did Charles think that this was acceptable behavior, and that Diana should just turn her back and ignore what was going on? Was he relieved that his wife was in her own extramarital affair? Did it affect him at all? It didn’t seem so,” she writes.

In one romantic gesture, Diana laid out a picnic for her and Charles at Highgrove, his country estate, but when the prince saw the table, “he immediately dropped her hand and said, ‘I don’t eat outside. Get the butler to take it all in immediately.’”

“In that instant,” Allan writes, “a bit more of her died. Her loving intention was destroyed by a few strong words.”

Diana told Allan, “I know he’s seeing Camilla again”, of her husband and Camilla Parker-Bowles (above).Shutterstock

Allan also portrays the famous moment Diana asked Camilla, of whom she was “quite frightened” to leave Charles alone at a birthday party for Camilla’s sister, Annabel Elliot, in 1989.

She writes, “At one point Camilla made a very strange comment that further propelled Diana. ‘You have everything in the world,’ Camilla said. ‘Men falling for you and two beautiful children. What more could you want?’ ‘I want my husband,’ was Diana’s firm reply.”

Di gleefully told Allan about the events of the “momentous” night and how, driving home together, Charles “was all over [her] like a little boy who has done something wrong and is wanting back in your good books.”

Camilla became Queen Camilla at the coronation she shared with King Charles in May 2023.ZUMAPRESS.com

“I thoroughly enjoyed hearing every detail, but more than anything loved Diana’s brave and bold accomplishment,” Allan writes.

Diana danced through both of her pregnancies, notes the author, who was one of the first people in whom Diana confided that she was expecting William.

Although Netflix hit “The Crown” shows Diana giving Charles a video of her performing “All I ask of You” from “Phantom of the Opera”, Allan says in fact, she secretly recorded herself performing to the theme tune from “Top Gun” for her sons — not Charles.

Diana fought with Charles over how to raise their sons, William (right) and Harry.Tim Graham Photo Library via Getty Images

The princess also found a sense of accomplishment in having Allan secretly record her performing to the theme song from “Top Gun” for her to share with her beloved sons. (The press at the time reported that she had recorded “All I Ask of You” from “Phantom of the Opera” for Charles. The Netflix hit “The Crown” also shows this.)

Diana laughed afterwards and sent Allan a letter saying she enjoyed watching the VHS.

“I see a lot of mistakes as do William & Harry who have great enjoyment pointing out mummy with her head down or ‘why aren’t you smiling,’ ” the letter read.

Diana, seen at the London Festival Ballet in Oslo, Norway, in 1984, had years of secret dance lessons with Allan.Shutterstock

But the fun was over when Beckwith-Smith asked for all the footage to be sent back to the palace.

“It turns out that they wanted to make sure the film did not get into the wrong hands. I was irate. My loyalty was being questioned, and being a Scot, loyalty and trust are huge things,” writes Allan, who does not reveal whether she still has the tapes in her possession.

When Allan moved back home to Scotland and then to Toronto their classes stopped, but she kept in touch with Diana.

Diana became patron of the London City Ballet.Tim Graham Photo Library via Getty Images

The last time the friends spoke was after the death of Diana’s father, Earl Spencer, in March 1992, the same year she and Charles officially separated. (They divorced in August 1996.)

She was left “numb” and devastated by Diana’s death in a car crash in Paris in August 1997.

Of Diana, she reminisces, “In our classes, she was nothing but her true self. Dance allowed the light within her to burn brighter, and I was given the extraordinary honor of being a part of it.