Mimi Alford says her 18 month affair with President John F. Kennedy was glamorous and fun, but also says the experience revealed a darker side of the king of Camelot. "I was sort of swept into this web," Alford told Meredith Vieira in an exclusive interview broadcast Wednesday night on NBC's Rock Center with Brian Williams. The handsome president, his charisma, his magnetism. Webs are sort of gentle, in a way. They're controlling, but they are gentle," Alford said. Half a century after the affair, it's still difficult for Alford to talk about the relationship that she says began when she was just 19 years old. "I don't think what I did at 19 was bad," Alford told Vieira through tears. "I'm remembering how enthusiastic I was and how much fun I was to be with," Alford said. I wasn't after anything. I wasn't after a job. I was just a young girl. Alford says that her sexual relationship with the 45-year-old Kennedy began in the summer of 1962, four days into her internship at the White House. She describes the affair as one where she and the president never kissed. Even in their most intimate moments, she called him Mr. President, never Jack, Alford says. It wasn't a romantic affair. I don't really remember the president ever kissing me and it, that makes me sad. I don't remember really kissing him either and I think really that I didn't, I certainly didn't learn how to have a real relationship through that relationship," Alford said. Now 68, Alford has written a book, Once Upon a Secret My Affair with John F. Kennedy and its Aftermath, sharing explicit details about her relationship with the president. She describes Kennedy as both "boyish" and "shy" around her, but also writes about witnessing his demons. While Alford and Kennedy's affair began in 1962, she first met the president a year earlier. In 1961, she was a senior at Miss Porter's School in Connecticut and was the editor of the boarding school's newspaper. She wanted to interview her school's most famous alumna, Jackie Kennedy. She didn't get the interview with the first lady, but she was invited to visit the White House and interview Mrs. Kennedy's social secretary, Letitia Baldridge. While visiting the White House, she met Kennedy briefly. A year after her article was printed, she was a freshman at Wheaton College in Massachusetts when she received a surprising offer of a job as a White House intern. Alford had never applied for the job. I was excited about this job. It seemed like a miracle," Alford said. And I was a little bit wide-eyed I think, not knowing exactly what to expect, but full of enthusiasm and hope. Parts of Alford's story are impossible to confirm because the people involved are no longer alive. However, NBC News talked to several people tied to the JFK administration who confirm that Alford was a White House intern and had special access to the president. An oral history by JFK White House aide Barbara Gamarekian references a beautiful intern named Mimi who Gamarekian suspected had an affair with Kennedy. Gamarekian is no longer alive. The First Encounter with Pres. Kennedy The debutante from a prominent New Jersey family headed to Washington, D.C. in the summer of 1962 to begin working in the White House press office. Four days into her internship, Alford says JFK aide David Powers invited her to go swimming. "He said, "A group of us are going to have a swim at lunchtime. Would you like to join us?"" Alford said. I think I was probably so taken in by being invited to go do it that I didn't think too much about it's odd, should I be doing this, should I not be doing this? I thought, no, I'll just go ahead and do it. Alford says she was joined by two others in the pool, White House staffers Priscilla Wear and Jill Cowan, who were playfully dubbed "Fiddle and Faddle." And while we were there, shortly after that, the president arrived. So I was sort of surprised that the president was joining us. No one had said the president was going to join us, but he went and put on his trunks and came into the water," Alford said. Alford finished her swim with the president and returned to work. It didn't seem unnatural. It sounds funny to say that, but it really didn't seem unnatural, just because everybody was friendly and this is what we were doing and I went back to work afterwards," Alford said. NBC News" calls to Priscilla Wear to confirm the story were not returned. Alford says that a few hours after her first swim with the president, she received another call from JFK aide Powers. This time he invited her upstairs to the White House residence for a welcoming of the new staff. "There was a pitcher of daiquiris on the coffee table and Dave [Powers] poured me one," Alford said. It was the first time she'd ever tasted a daiquiri. "And then the president arrived," Alford said. He sat down, very relaxed, put his feet up on the coffee table and sort of joined in on the conversations...Obviously these were the people that he liked to relax with and then there was I, which seemed a little odd, but I didn't think much about it. Alford says Kennedy singled her out and asked if she wanted to take a private tour of the rooms his wife had recently redecorated. "There was nothing in my mind that thought anything other than what I was being offered which was a tour of what the White House looked like," Alford said. Kennedy led Alford on the tour, which she says ended in Jackie Kennedy's bedroom. "I felt the president getting closer and closer to me," Alford said. "His way didn't make me nervous and he came close, very close, and looked me right in the eyes and I actually, he then put his hands on my shoulder and sort of guiding me down to the edge of the bed, sort of the corner of the bed and I think he may have even said to me, "Is this all right..."I don't really think I knew what he was talking about." Alford says she was a virgin who had only kissed a boy when she was in eighth grade. Obviously what did happen was I lost my virginity right there. Then, I think I went a little bit into shock," Alford said. He kept asking me if I was all right and I was all right, there was not a lot of conversation. In her memoir, Alford writes that Kennedy "maneuvered me swiftly and unexpectedly and with such authority and strength that short of screaming, I doubt if I could have done anything to thwart his intentions." Decades later when Alford confided in friends and family, some questioned whether she was raped by Kennedy. I don't consider it was rape. I don't," Alford said. If I had said no, I think the president would have stopped, but I didn't...there was no coercion. A few days after her first tryst with Kennedy, Alford says she was invited again to the private floors of the White House. "I had just a little bit of second thoughts, not enough to keep me from going back," Alford said. Alford describes this as a pivotal point in her relationship with Kennedy saying that it marks the beginning of their secret affair. Rubber Ducks, Cooking with Kennedy and Special Hair Treatments In her book, Alford calls her sexual encounters with Kennedy varied and fun, describing the president as a sensualist who also enjoyed being completely silly, especially in the bathtub. "He had a collection of little yellow rubber ducks and they were in the bathtub and rubber ducks became sort of part of the game," Alford said. We had races with rubber ducks in the bathtub. I know he was not being president when he was with me. She says Kennedy taught her how to cook eggs in a double broiler the way he liked them. They listened to records. "I think maybe I reminded him of a younger time in his life," Alford said. She says that she even learned how to help Kennedy keep his hair perfectly coiffed by performing special hair treatments. I ended up taking care of the president's hair. He had this, he had that wonderful hair and it always needed to be in great shape and so I learned how to do the head treatments," Alford said. Alford says that she sometimes performed the hair treatments in the Oval Office. Alford says that during her internship, she would sometimes spend the night at the White House, but nobody would ever acknowledge the affair. "Secret Service might have known, but nobody ever talked to me about it," Alford said. She traveled on occasion with the president, flying on the support plane in her role as press office intern. On one trip, she says that she ended up at a party at Bing Crosby's home in California. It was exciting. It was glamorous, it was fun," Alford said. During many of her trips with the president, Alford says that she often played the "waiting game," spending hours in a hotel room waiting for Kennedy to pay her a visit. He was married to Mrs. Kennedy, but I didn't at the time feel guilty because I think I felt this closeness to him," Alford said. Looking back now, Alford realizes she was at the beck and call of the 45-year-old president. "I can see it's not a good place for a 19-year-old to be in a relationship that's so imbalanced and with such a powerful person and an older man and at the beck and call," Alford said. I see how sad it was. Kennedy's Request to "Take Care" of Aide, Ted Kennedy While Alford says the president made her feel special, she also says that he had a "dark side." The most disturbing incident occurred at the White House pool, Alford says. JFK aide Powers was sitting poolside while Alford and Kennedy swam. Alford claims Kennedy whispered in her ear that Powers looked tense and asked her, "Would you take care of it." Alford writes in her book, "I knew exactly what he meant. Take care of it. That was a challenge to give Dave Powers oral sex. I don't think the president thought I'd do it, but I'm ashamed to say that I did. An emotional Alford told Vieira that the incident still makes her sad and angry. "It makes me angry because I didn't just splash water in the president's face and tell him to get lost," Alford said. It makes me sad because I did it. JFK aide Powers died in 1998, before Alford came forward with her secret. Alford claims the president asked her to "take care" of his brother, freshman Senator Ted Kennedy, in the fall of 1963 towards the end of their affair, but she refused. Pregnancy Scare and the Cuban Missile Crisis When Alford returned to college in the fall of 1962, she briefly panicked that she might be pregnant. She says she contacted JFK aide Powers. "He said that he would put me in touch with someone who would put me in touch with someone who would put me in touch with someone down the line if I should need help and luckily I didn't," Alford said. Alford says that she and Kennedy continued their relationship. She says that they devised a nickname, "Michael Carter," for Kennedy to use when calling her dorm. When a phone call wasn't enough, Alford says the president would brazenly make arrangements to bring her back to Washington, D.C. She claims that even returned to visit the president during the tense night before the Cuban Missile Crisis was resolved. "I think the president wanted me to be there," Alford said. I really didn't spend much time with the president. I was just there. She didn't sleep with the president that night. Alford returned to the White House as an intern again in the summer of 1963. She was in charge of photo sessions in the Oval Office which meant she saw the president almost daily. Since Jackie Kennedy was pregnant, Alford says she had limited access to Kennedy after hours. Alford never met the first lady and she says Kennedy only discussed his family with her after the death of his newborn son, Patrick, in August 1963. Patrick Kennedy died of an under developed lung syndrome shortly after birth. As the fall neared, Alford was falling deeper in love with Tony Fahnestock, a college student she'd been dating since the beginning of 1963. She kept her relationship with Kennedy secret from Fahnestock. When she and Fahnestock became engaged, Alford says Kennedy congratulated her. "He was happy for me and sort of joked that, "Oh, well, you're not going to leave me are you?" So it was a kind of complicated thing for me, but he was happy that I had met Tony. Alford says that Kennedy gave her two gold pins with diamonds in the center of them as a present and an autographed picture that said, "Warm regards and best wishes and appreciation." He joked that no one would ever know what he was really appreciating her for, Alford says. Once she was engaged, she says the dynamics of her relationship with Kennedy shifted from being sexual to more of a friendship. Kennedy's Assassination and Burying the Secret Alford says the last time she saw Kennedy was 15 days before he was assassinated. She says that they saw each other at the Carlyle Hotel in New York City on Nov. 15, 1963. Alford claims Kennedy gave her $300 as a wedding gift and promised to call when he returned from Texas. Seven days later, the president was dead. Alford heard the devastating news when she and her fiancé were driving to his family's home in Connecticut. I could hardly breathe. I was in so much pain," Alford said. Here was Tony who I was going to marry, who I loved, there was the president who I had loved, who I had spent 18 months with, he was dead. The feelings were just explosive inside me. Her grief stunned her fiancé, prompting him to probe about her relationship with Kennedy. She confessed the affair. It was the first time she'd told anyone. "Tony's reaction was emotionally violent," Alford said. "His response was so devastating that at that moment what happened for me was I just shut down emotionally...because what Tony said to me was, "you and I will never ever talk about this and you are never to tell anybody else."" Alford buried the secret and says that she shut down emotionally. She did her best to cover up her past, never mentioning her summers as a White House intern on resumes and getting rid of gifts Kennedy had given her. She cut up the autographed picture and pawned the gold and diamond pins. "It's very hard to live without telling people," Alford said. Alford and Fahnestock married in 1964. In a sadly similar twist of fate to Mrs. Kennedy, Alford lost her first baby to the same under developed lung syndrome that had taken Patrick Kennedy. Alford went on to have two healthy baby girls. No Regrets and Moving Forward Alford says that her emotional shutdown impacted her marriage to Fahnestock, leading to their eventual divorce. Still, she doesn't regret the affair. I don't actually regret that I had the affair with President Kennedy. What I regret is that I was shut down emotionally," Alford said. Alford told Vieira that she wishes she'd told her parents about the secret relationship. "I think they died not knowing all of me," she said. The story of Alford and Kennedy's alleged affair was first mentioned in 2003 when historian Robert Dallek mentioned a beautiful intern who was believed to be one of Kennedy's paramours in a biography of Kennedy. When the New York Daily News tracked her down, Alford submitted a written statement acknowledging the affair, but did not speak publicly. Shortly after the story became public, she met her current husband, Dick Alford. Mimi Alford says his encouragement helped her confront her past and led her to write her memoir, even though she knows she will have critics. People are going to judge me. There's nothing I can do about that. All I can say is that, for me, to write this book, Once Upon a Secret, was extremely important. I had to do it...I can't separate the Kennedy name from it. This was part of the story," Alford said.