In June of 1979, Maureen O’Hara received word that her great friend and frequent co-star, John Wayne, had died at age 72. “That’s the only time I had ever seen my grandmother cry,” Conor Beau Fitzsimons tells Closer. “She didn’t really cry when her husband died. But when Duke died, she cried.”

John, known as Duke to his friends, and Maureen starred in five films together and enjoyed one of Hollywood’s warmest and most enduring relationships. Their spirited on-screen chemistry often led to speculation that they were lovers in real life, too. Although the pair always laughed it off, Maureen’s grandson confides that they did have a brief real-life romance. “I know they did at one point, but she was way too strong for him,” says Fitzsimons. “They would never have been a good couple.”

The Dublin-born Irish beauty first met Duke through director John Ford, who would become a close friend to both actors. Ford cast them together in 1950’s romantic western Rio Grande, the film where Duke returned to the role of Capt. Kirby York. Maureen was introduced as his estranged wife — a pairing that fans immediately loved. “Duke’s presence was so strong that when audiences finally meet a woman of equal hell and fire, it was exciting and thrilling,” Maureen said.

Despite her Technicolor-ready looks, the stunning redhead could hold her own among the men in many ways. “They used to go up Ford’s house and drink a few whiskies. Back then, there were not a lot of women that could hold their whiskey and stay up late like my grandmother,” says Fitzsimons, who adds that Maureen would often sit at the piano and play and sing at these informal gatherings. “She got a reputation as one of the boys.”

Maureen appreciated being seen as a person, not a pretty plaything. In 1945, she was among the first actresses to talk openly about Hollywood’s casting couch — and it almost cost Maureen her career. “I’m a helpless victim of a Hollywood whispering campaign. Because I don’t let the producer and director kiss me every morning, or let them paw me, they have spread word around town that I am not a woman — that I am a cold piece of marble statuary,” she complained.

Around Duke and Ford, she felt safe. “I think my grandma didn’t like when men hit on her too much,” says Fitzsimons. “When she wanted to socialize, drink and just be Maureen, she knew that Duke always had her back.”

Maureen and Duke did surrender to their mutual attraction and affection for each other once. “I’m pretty confident it was only the one time,” says Fitzsimons. “You can’t have those [tender] looks that they had in the movies without having a moment in time.” Until her death in 2015 at age 95, Maureen kept a hotel room key as a souvenir of her night with Duke. On a card she kept with the key, she had written: “better as friends.” Says Fitzsimons: “They would have been friends first, and most of the Duke’s dames were not his friends. I think that night might have cemented their friendship.”

In fact, Maureen took it as a great compliment that Duke considered her a pal. “There’s only one woman who has been my friend over the years, and by that, I mean a real friend, like a man would be,” Duke gushed. “She’s big, lusty and absolutely marvelous, definitely my kind of woman. She’s a great guy. I’ve had many friends, and I prefer the company of men. Except for Maureen O’Hara.”

In many ways, Duke and Maureen became family. She even became close to Duke’s second and third wives. “She was a loving friend and not a threat,” says Fitzsimons, who adds that his grandmother’s fluency in Spanish helped her bond with Duke’s wives, who both had Hispanic heritage. “They were able to make little jokes about him without him understanding,” Fitzsimons says.

Duke and Maureen saw each other through marriages, divorces, the birth of children, illness and the ups-and-downs of two stellar Hollywood careers. “I think he valued the conversations he had with her. He could be honest and get a feminine opinion from Maureen,” says Fitzsimons, who as a boy went fishing with Duke when they were both guests of his grandmother.

Maureen, who is being honored with a new exhibit at Foynes Flying Boat & Maritime Museum in her native Ireland, encouraged her young grandson to look to Duke as a role model. “I didn’t have a father when I grew up, and Maureen definitely pushed that this is the kind of man you want to be when you grow up. My impression of that was a man who opened doors, was respectful, loved the Constitution and America,” he says. “I would say that Duke really help mold who I became.”