Joseph P. Kennedy, 1938

John F. Kennedy’s many affairs – including a possible relationship with Marilyn Monroe — are legendary, but it turns out his father was just as amorous. Joseph P. Kennedy Sr. probably had affairs with Hollywood stars Gloria Swanson and Marlene Dietrich in the 1920s and 1930s.

According to Swanson’s memoir, she and Joe Kennedy met on November 11, 1927 at the Savoy Plaza Hotel in New York City. A mutual friend had put them in touch because Swanson needed financial advice that Kennedy, a banker, could provide. She was already a major star, but her extravagant lifestyle had left her in debt. Looking back, she said, "In those days the public wanted us to live like kings and queens. So we did — why not?" (via The Washington Post).

Kennedy bluntly asked her why she had turned down a million-dollar per year contract from Paramount. "I would have been the second or third person in movie history to sign a million-dollar contract," she said, "but I was the very first one to turn it down." The Washington Post says Kennedy found this amusing, and Swanson kept trying to make him laugh. From there, the affair developed quickly. Swanson and her then-husband visited Kennedy in California, and Kennedy sent her husband on a day-long fishing trip so he could have Swanson to himself, according to Medium. He came to her room and said he couldn’t wait any longer. The encounter was "hasty," she wrote, but passionate (via The Washington Post).

Kennedy wasn’t sexually satisfied in his marriage

Rose Kennedy and Joseph Kennedy

One reason Kennedy had affairs is that his relationship with his wife, Rose, was fairly chaste. According to her close friend Marie Greene, Rose Kennedy, a devout Catholic, believed that sex should be reserved for the purpose of procreation only. Swanson was a much more modern woman with different moral values. When Joe Kennedy’s affair with Swanson began, Rose Kennedy was in Massachusetts expecting, and then giving birth to, their eighth child. After the birth of their last child, Ted, the Kennedys stopped having sex (via The Washington Post).

Rose Kennedy probably knew about her husband’s affair with Swanson, but she always claimed her husband was simply helping Swanson with finances. She seemed to feel sorry for Swanson. If she was ever jealous or angry, she didn’t show it publicly. After all, she had the advantage of being Kennedy’s wife and the prestige and financial advantages that came with that.

Her parents weren’t equally resigned to the affair. According to The Washington Post, Rose Kennedy’s niece reported hearing John Fitzgerald, Rose’s father, threatening Joe Kennedy that he would expose the affair. Kennedy replied that if Fitzgerald told Rose the truth, he’d simply marry Swanson instead. Later, Rose Kennedy’s mother was the one to tell her about the affair, but Rose chose to look the other way.

Kennedy and Swanson’s professional collaboration was a failure

Gloria Swanson with a cigarette

Gloria Swanson was married six times, and her last husband described her as Joe Kennedy’s "ultimate trophy mistress." She later wrote that Kennedy had "taken over [her] entire life" (via Medium). He did this mainly by rearranging her finances and the ownership of her most recent films. By the end of her affair with Kennedy, she was actually in more debt than before, because she hadn’t received as much money as she should have from her popular film "Sadie Thompson," and because Kennedy had charged many of the expenses of the film "Queen Kelly" to her accounts.

Kennedy and Swanson collaborated on "Queen Kelly," but the production was a disaster, according to Medium. Kennedy hired Erich Von Stroheim to direct it, and Von Stroheim was notorious for production delays and other complications. "Queen Kelly" was no exception, and eventually, Kennedy needed to replace his director but couldn’t find a new one. The script changed repeatedly, and the production was enormously expensive. Adding to the catastrophe, when the film finally came out, it was a box office flop.

Just after this, in 1931, Kennedy left Hollywood and seemed to be done with filmmaking. His affair with Swanson was over, too.

Dietrich met Kennedy on the French Riviera

Marlene Dietrich on French quay

Seven years later, age 49, Kennedy was the U.S. ambassador to England. He was summering with his family in Cannes on the French Riviera and rented a villa near the Hôtel du Cap, where many rich and famous people stayed. It was there that he met film star Marlene Dietrich. She later recalled that Kennedy "started following [her] around" (via Vanity Fair).

Dietrich was married to Rudolf Sieber, and they had a daughter, but it was an open marriage and both took other lovers. She was 37 when she met Kennedy and already having an affair with writer Erich Maria Remarque ("All Quiet on the Western Front," 1928). She was also in a professional slump, so Kennedy tapped into his old network of Hollywood contacts to help her negotiate a role in a western that would revive her career.

Kennedy and Dietrich had similar personalities and loved to talk politics together, although she didn’t agree with his isolationist policies toward Nazi Germany. His stance wasn’t popular in general and eventually lost him his post as ambassador. He and Dietrich rekindled their affair the following summer, 1939, just before World War II broke out. Kennedy helped her family get out of Europe as Dietrich herself returned to Hollywood to work on the western "Destry Rides Again" (via Vanity Fair).

Dietrich’s daughter became close with the Kennedy children

Marlene Dietrich and Maria Sieber

While their parents were carrying on an affair, the Kennedy children made friends with Dietrich’s teenage daughter Maria Sieber. Despite a six-year age gap, she became especially close to Rosemary, the Kennedys’ intellectually delayed oldest daughter. Sieber said they bonded because "we were both shadow children" (via Vanity Fair).

Sieber noticed her mother’s closeness with Joe Kennedy and worried it would affect her friendships, but the Kennedys, including Rose, continued to treat her well. Sieber was excited to see them again the following summer.

Sieber had a bit of a crush on John F. Kennedy. She later remembered how he gallantly asked her to dance at a ball in Cannes. She was wearing her first-ever evening dress, which she described as looking like a mosquito tent. She said, "A breathtaking dream who, at the age of just 21, has the kindness to ask a net tent to dance, you must admit is truly wonderful!" (via Vanity Fair).

Dietrich may have also had an affair with JFK

JFK with presidential seal

That ball was also significant for John F. Kennedy, because it was, in a sense, the night his own affair with Dietrich began. According to Vanity Fair, George Jacobs, Frank Sinatra’s valet, described in his memoir how JFK told him about that night: He was dancing with Dietrich when she felt him up.

The two reconnected years later when JFK was president. Dietrich was performing in Washington, D.C., and JFK invited her to the White House. Two different friends of Dietrich’s, Kenneth Tynan and Gore Vidal, recalled her description of that night. According to Vanity Fair, she and JFK ended up alone together, and he made a "clumsy pass" at her. She pointed out that she was rather old — over 60 — but he didn’t care, apparently. They had "an ecstatic three to six minutes" together, after which JFK fell asleep. She had to wake him to help her find her way out of the White House, as she was late for an event.

Before she left, JFK asked her if she’d ever slept with his father. She said no, which was what JFK wanted to hear (via Vanity Fair). Whether it was the truth remains a mystery.