For 40 years, Mimi Beardsley Alford kept her mouth shut about the 18-month-long sexual affair she had with President John F. Kennedy that lasted until his assassination in 1968, the Telegraph reports. She didn't even mention it to her parents or children until a Kennedy biographer outed her in 2003. Now, Alford has signed a book deal with an advance reportedly close to $1 million. According to Alford's agent, the book won't be a tell-all about the affair, which took place when Alford was a 19-year-old White House intern, but will be a memoir that details a young woman's coming of age and ensuing loss of innocence, and that discusses the consequences of keeping such an explosive secret. And there's an odd coincidence: Alford and Jackie O. even went to the same tony private high school, albeit years apart.