Zachary Hitchcock Collection A bombshell new book,JFK: Public, Private, Secretby J. Randy Taraborrelli, comes out July 15 and PEOPLE has an exclusive first excerpt It reveals that JFK had an affair with a flight attendant named Joan Lundberg, resulting in her pregnancy Below, read what happened — and how Jackie reacted to her husband's affairs Joan Lundberg was "one of a kind," says her son Zachary Hitchcock. "She was unconventional and independent — a voluptuous beauty with a great smile." According to a bombshell new biography,JFK: Public, Private, Secretby J. Randy Taraborrelli, the young flight attendant met JFK in 1956 when he was a senator from Massachusetts — and married. It's a little-known chapter in the life of the 35th president and might have remained that way were it not for Lundberg's family, who shared her unpublished memoir and personal diaries with Taraborrelli. For more on JFK and Joan, pick up the latest issue of PEOPLE, on newsstands Friday, or subscribehere. The author tells her story in detail for the first time in his new book, a follow-up to his 2023 biography,Jackie: Public, Private Secret.Says Taraborrelli, "With this book, I wanted not to defend JFK but I wanted to explain him." "Joan was a big revelation for me," the author adds. "She acted as his therapist in many ways. Because she was outside of his Washington circle, he opened up to her — and began to reckon with his flaws." By weaving Lundberg's story and portions of her manuscript into his new book, he says, "You're left with a portrait of a very interesting woman." Learn more below, in an excerpt fromJFK: Public, Private, Secretshared exclusively with PEOPLE. St. Martin's Press On August 19, 1956, the senator from Massachusetts met Joan Lundberg, 23, standing in front of the jukebox at The Sip and Surf, a dive bar in Santa Monica, Calif. "What are you gonna play?" he asked her. "I was thinking Elvis Presley, but what would you like to hear?" she asked. He said he wanted to hear something "so I can concentrate on you." Corny, but not bad. Joan, a single mom of two, was then living with a man named Norm Bishop and working as a flight attendant for Frontier Airlines (and as a cocktail waitress on the side). When Jack asked where she lived, she told him it was in a "trailer court close by," not hesitating. "What the hell's a trailer court?" he asked. She laughed and answered, "You don't want to know." After about 15 minutes Jack, then 39, said goodbye and returned to his friends. Half an hour later, bar owner Pat Dorian called her to the phone. She picked it up. "How ah ya?" came back the voice with its broad Bostonian accent. It was Jack. He was leaving town tomorrow for Italy but would return in two weeks. On Aug. 24 Jack found out Jackie, then 27, had given birth to their stillborn daughter Arabella. Four days later he returned to Hammersmith Farm, her family's estate in Newport, R.I., where she was recuperating — and fed up. Robert Knudsen. White House Photographs. John F. Kennedy Presidential Library and Museum, Boston She'd always felt something was missing in his nature, and now she knew what it was: empathy. When Jackie wept at the breakfast table and said, "How could I have been so stupid?" her mother, Janet, reached out and took her hand. "You're not stupid," she told her. "You just put your trust in the wrong person." In early September, Jack returned to L.A. and invited Joan to a dinner party at the home of his sister Pat and her husband, actor Peter Lawford. Joan later remembered feeling insecure and out of her element, though she certainly looked stylish in an outfit from Jax in Beverly Hills, a boutique favored by Marilyn Monroe. She would later write: "He lit up the room. People came over just to be near him, his energy magnetic. I thought, well of course, that's the politician in him. But I soon realized that, no, that's just who he is." At about midnight, Jack drove Joan up Pacific Coast Highway to a nondescript 1930s motor court called the Sunset Motel. They checked in as "Mr. and Mrs. Robert Thompson." The sex that night was "wild," claimed Joan. The next morning over breakfast, he unburdened himself. His fears, his insecurities. It was as if she was so removed from his circle, he could share anything. According to what Joan later recalled, Jack admitted that he and Jackie were the product of "an arranged marriage" and, as such marriages go, he said it was "fine. Not great, but okay." Jack said his family had turned against him for not being there for Jackie after Arabella's stillbirth. He admitted that "We Kennedys aren't the best at expressing emotion." Joan told him, "I'll bet that's the great excuse of your life." Joan asked him if he'd grown to love his wife. He hesitated. "I don't know that I love anything," was his answer. That can't be true, she said. After a moment, he added, "I love politics. I don't know how to love anything else." Jack Kennedy had no sooner walked into the foyer of Hammersmith Farm upon his return to Newport when Jackie hit him with a question: "Who's Trailer Park Joan?" As he collected his thoughts, she clarified things: "The divorcée! Your sister told me all about her!" He explained that Joan was someone he'd met in Los Angeles. Joan is vague in her unpublished memoir about how much Jack told Jackie, only that he told her pretty much everything. Within weeks his father, Joe Kennedy, got a call from a top New York attorney who'd been retained to represent Jackie in a divorce. Joe met Jackie for lunch in New York to talk about it. Joe told Jackie that if she agreed to stay in the marriage he could give her the freedom to do whatever she liked. He would offer her $100,000 upon the birth of her and Jack's first child. Jackie accepted the offer but had to find a way to cope with her husband's infidelity. The PEOPLE Appis now available in the Apple App Store! Download it now for the most binge-worthy celeb content, exclusive video clips, astrology updates and more! Many years later, Jackie told architect John Carl Warnecke, "He didn't have to lie to me about this Joan woman. I was already lying to myself." Warnecke recalled, "She told me things changed for her when Jack became involved with Joan but that it wasn't a subject she wanted to get into. It was very painful, that much I knew." By 1957 JFK was being talked about as a presidential contender. In private he continued his affair with Joan, flying her to meet him on different airlines and covering her expenses. "She told me, 'I never worry about trouble when I'm with Jack because I pass for his sister, Pat, all the time,' " said Joan's sister, Linda Lydon. Joan later recalled that she and Jack got along well, "aside from normal lovers' tiffs between two high-spirited people." They often discussed his political career, with him starting off sentences with, "When I'm president . . ." One night in May [1957] Jack and Joan were sharing a cigarette in bed when he suddenly asked her, "Tell me the truth, Joan. Do you think Jackie is screwing other guys?" He explained that Jackie was "so great," he couldn't imagine her not having someone else in her life. At the beginning of the year, he said, they'd started having sex now and again, but "there's too much left unspoken between us." Recently after having sex, she'd asked him, "What you do with me in bed, is that what she likes?" obviously meaning Joan. He could see the "damage in her eyes," he said, "and it killed me." Zachary Hitchcock Collection After Jackie gave birth to Caroline on Nov. 27, Joan noticed a change. She later wrote: "I think I was now very much in love, and I was so mad at myself because I knew better. I knew better!" While Jack and Joan would again share their bed in Minneapolis on April 25 and 26, 1958, things were definitely different. On June 25, according to her calendar, Joan called Jack. She was pregnant. Joan would recall that her news about the baby was "like a knife to Jack's heart." While it was a shock, Joan wrote that they shouldn't have been so surprised: "I didn't like wearing a diaphragm, and Jack wouldn't wear a rubber," she wrote. Jack couldn't help but wonder if Joan had purposely planned the pregnancy given that she'd seen his devotion to Jackie after Caroline's birth. He also wondered if he was really the father, and Joan assured him he was. When he asked her how she felt about the pregnancy, she said she loved the two children she was raising on her own and knew she'd also love any child she and Jack brought into the world. He didn't know how to respond. "I have no words," he said. "Find some," she told him. He took both her hands in his own. "I'm so very sorry, Joan," he told her. "I am, too," she said. Later that summer they had a tense phone call. Sounding edgy and not like himself, he told her he'd decided she couldn't have the baby. Joan tried to argue, but she didn't know how. Jack said that he'd mail her $400. He told her, "You'll know what to do, Joan. Please," he said, his tone desperate. "Being a politician is who I am," he told her. "Politics is all I know. If you take that away . . ." His voice trailed off. Before she could respond, he disconnected the line. A week later she got an envelope with no return address. It was empty. She told him the money had been stolen. He became positively unhinged. Joan later wrote: "My God! You had never heard anybody use expletives so much in the whole history of Washington." Jack was very clear; he didn't want Joan to have the baby. He wired more money that same day, and she took care of things a day after that. She was angry and disappointed, but also realistic. "From what she later told me, Mom realized the party was over," said Zachary Hitchcock in 2024. "She couldn't be on the sidelines. The presidency, Jackie, the abortion, there was no way mother could be marginalized in that way. She had way too much pride." Never miss a story — sign up forPEOPLE's free daily newsletterto stay up-to-date on the best of what PEOPLE has to offer , from celebrity news to compelling human interest stories. It ended not in person but on the phone. When Jack called Joan to check on her, she told him, "I'm going to need to put some distance between us." He understood. "I owe you so much," he told her. "One thing I want to say to you, Kennedy," she told him. "You love Caroline, and I know that, but I'm somebody's daughter, too. Remember that the next time you treat a woman the way you've treated me." On Nov. 8, 1960, he became the 35th president. His relationship with Joan never came to light. But Jackie did install a spy, a woman she recommended for a job in the office of JFK's personal secretary Evelyn Lincoln, to keep her posted of suspicious calls. From all available evidence, Jackie never found out about the abortion, either. Many years later, she told a family member, "I was doing my best with the cards I'd been dealt. I loved Jack. I know he loved me. I had to ignore the rest of it. My marriage was like a deep black hole and I knew if I looked down, I'd fall in." Kennedy had a telling conversation with his friend Florida senator George Smathers in early 1962. "Do you worry Jackie will find out about the other women?" George asked. Jack became instantly frustrated. "There are no other women. I've never told any other woman I love her. There is only Jackie. Besides," he said, "we could all be blown up in an atomic war tomorrow. That's what worries me. Not this bullshit." After their son Patrick died on Aug. 9, 1963, two days after being born prematurely, Jackie decided to travel with her husband to Dallas that November. A couple of months earlier, at the celebration of their tenth wedding anniversary, Jackie and Jack gave each other gifts. She presented him with a new St. Christopher's medal because he'd placed his own in Patrick's coffin. In turn, he gave her a gold-and-emerald ring, which represented the fighting spirit of the Irish he'd seen in their son's fight for survival. He slipped it onto Jackie's finger next to her wedding band and asked her to marry him. There'd never been a real proposal, except for a few words in an airport when she returned from her trip to England in 1953. Jack was a different man. They planned a private ceremony to renew their vows for September 1964 at Hammersmith,marking their 11th wedding anniversary. Jackie planned to wear a pale blue or yellow dress.But it never came to pass. Joan [who had married Freemont Hitchcock in 1963] was devastated by the assassination. She wrote: When the truth struck home, I closed my bedroom curtains and shades, and I cried, screamed, and cursed alone for hours. Excerpted fromJFK: Public, Private, Secret,copyright © 2025 by J. Randy Taraborrelli, with permission from St. Martin's Press. JFK: Public, Private, Secretcomes out July 15 and is available now for preorder, wherever books are sold. Read the original article onPeople