The cover of "Once Upon A Secret." (Courtesy Random House)

The book, written by Mimi Alford, then Mimi Beardsley, circles around her experiences as a 19-year-old working in the White House Press Office while John F. Kennedy was in office. The details are less than flattering, and some have been described as outright scandalous.

The Los Angeles Times published an excerpt via the New York Post:

Four days into her internship, she was invited by an aide to go for a midday swim in the White House pool, where the handsome, 45-year-old president swam daily to ease chronic back pain. JFK slid into the pool and floated up to her.

“It’s Mimi, isn’t it?” he asked.

“Yes, sir,” she said.

“And you’re in the press office this summer, right?”

“Yes, sir, I am,” she replied.

Lightning had struck. Later that day, Mimi was invited by Dave Powers, the president’s “first friend” and later the longtime curator of the Kennedy Library in Boston, to an after-work party. When she arrived at the White House residence, Powers and two other young female staffers were waiting.

Powers poured, and frequently refilled, her glass with daiquiris until the commander-in-chief arrived.

The president invited her for a personal tour. She got up, expecting the rest of the group to follow. They didn’t. He took her to “Mrs. Kennedy’s room.”

“I noticed he was moving closer and closer. I could feel his breath on my neck. He put his hand on my shoulder,” she recounts.

According to the book, Alford alleges the affair lasted 18 months with the former President, and she saw him as late as a week before he was assassinated. In the except released to the Post, Alford claims Kennedy took her virginity.

The AFP reported:

The young debutante, described by one Kennedy biographer as a "tall, slender, beautiful" college sophomore, continued the relationship for a year and a half -- even traveling with the president on occasion -- until their affair ended with Kennedy's assassination.

Although they never kissed, and there was always a "layer of reserve between us, the sex was "varied and fun" she said, although Kennedy sometimes "acted like he had all the time in the world. Other times, he was in no mood to linger."

During their affair Kennedy reportedly taught Alford to make scrambled eggs and to appreciate the music of Frank Sinatra and Tony Bennett. Despite their intimate liaison, she continued to call him Mr. President.

And she explains in her book that it never occurred to her to resist the advances of the leader of the free world.

"The fact that I was being desired by the most famous and powerful man in America only amplified my feelings to the point where resistance was out of the question. That's why I didn?t say no to the president," she wrote.

And when she finished her stint at the press office of the White House, and returned to Wheaton College in Massachusetts, he sometimes would call her under the pseudonym Michael Carter.

The last time she saw him was on November 15, 1963, a week before Kennedy was gunned down in Dallas. "I'll call you when I get back," he told her. Alford reminded the president that she was soon to get married.

"I know that, but I'll call you anyway," he replied.

Alford, now 68, lives in New York City and works as a church administrator. She is scheduled to appear on NBC's "Rock Center with Brian Williams" on Wednesday night to discuss the book.