It may be the most explosive book about Camelot ever.
The author says she had a passionate affair with JFK when she was a 19-year-old White House intern.
In Once Upon a Secret, Mimi Alford says JFK took her virginity in Jackie Kennedy's bedroom.
Now, 69-years-old and a grandmother, she writes: "I noticed he was moving closer and closer. I could feel his breath on my neck. He put his hand on my shoulder."
She told NBC's Meredith Vieira who conducted the interview for Rock Center, airing Wednesday night, she felt overpowered.
"I think overpowered in the sense that he was the President. He was this unbelievably handsome man, 45-years-old. [I was] not overpowered physically that someone grabbed me and made me do something I wasn't really willing to do but I really think I was willing to do it," said Alford.
But she also reveals an even more shocking secret. She says JFK asked her to perform a sex act with one of his aides in the White House pool.
"It was a dare. I don't think the President thought I'd do it, but I'm ashamed to say that I did. The President silently watched." she writes.
Alford got her White House internship through family connections. She says even after her internship came to end, JFK continued to arrange rendezvous, including at the posh Carlyle Hotel in Manhattan just weeks before the assassination in 1963. For all these years she's kept silent, until now.
"When you keep a secret and when you keep silent about it, about something, you do it because you think it's keeping you safe, but in fact, it's deadly," says Alford.
The sordid details she reveals are getting mixed reviews. Barbara Walters called the affair sleazy on The View on Monday.
Walters said, "This is so raw, that it is disturbing to think about. This is particularly sleezy."