The book isn't supposed to be available until Wednesday but the Post said it bought a copy at a Manhattan bookstore.

The newspaper said Alford writes that she was just four days into her internship in the White House press office when she was invited by an aide to go for a swim in the White House pool. She says the president got into the pool and talked to her briefly. Later in the day, presidential friend Dave Powers allegedly invited her to an after-work party at the White House residence.

She said she drank several daiquiris and Kennedy later invited her for a personal tour that culminated with the two having sex in a bedroom used by first lady Jackie Kennedy.

"After he finished, he hitched up his pants and smiled at me," she wrote, adding afterward she was "in shock."

"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."

Alford says she later pondered whether she could have resisted Kennedy's advances.

"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," she wrote. "That's why I didn't say no to the president. It's the best answer I can give." (UPI)