( CNN ) -- The author of a new tell-all book claims she lost her virginity to President John F. Kennedy when she was a 19-year-old White House intern , and that the affair lasted 18 months . The book , `` Once Upon a Secret : My Affair with President John F. Kennedy and Its Aftermath , '' will be available Wednesday , but CNN was able to buy a copy Monday . The alleged affair began in the summer of 1962 , while Mimi Alford worked in the White House press office . She met Kennedy four days into her internship , and was invited for a personal tour of the residence a day later by the commander-in-chief after being served daiquiris , she says in Chapter 4 of the book . `` Slowly , he unbuttoned the top of my shirtdress and touched my breasts , '' Alford said in the book . `` Then he reached up between my legs and started to pull off my underwear . I finished unbuttoning my shirtdress and let it fall off my shoulders . '' `` After he finished , he hitched up his pants and smiled at me '' pointing her to the bathroom . `` I was in shock , '' she writes . `` He , on the other hand , was matter-of-fact , and acted as if what had just occurred was the most natural thing in the world . '' The White House arranged for a car for her , she said . On the ride home , it `` kept echoing in my head : I 'm not a virgin anymore . '' `` In an era when women in the workplace were still considered 'girls , ' Mimi was literally a girl herself -- naive , innocent , emotionally unprepared for the thrill that came when the president 's charisma and power were turned on her full-force , '' according to the website of the book 's publisher , Random House . `` She was also unprepared for the feelings of isolation that would follow as she fell into the double life of a college student who was also the secret lover of the most powerful man in the world . '' Fifty years later , Alford is now a 69-year-old grandmother and retired New York City church administrator , the Post reported . Following Kennedy 's assassination , Alford `` grieved in private , locked her secret away and tried to start her life anew , only to find that her past would cast a long shadow -- and ultimately destroy her relationship with the man she married , '' Random House said . In 2003 , a Kennedy biographer mentioned `` a tall , slender , beautiful 19-year-old college sophomore and White House intern , who worked in the press office '' when referencing one of the president 's affairs , the publisher 's website said . `` The disclosure set off a tabloid frenzy and soon exposed Mimi and the secret that she had kept for 41 years . '' The publisher describes the book as `` a new and personal depiction of one of our most iconic leaders and a powerful , moving story of a woman coming to terms with her past and moving out of the shadows to reclaim the truth . '' CNN 's Dominique Dodley contributed to this report .
Mimi Alford is now a 69-year-old grandmother . She was born in the Bronx and grew up on Staten Island with her parents. `` I 'm not a virgin anymore , '' Alford recounts after first encounter with Kennedy . The alleged affair took place in the summer of 1962 , according to her book .