Lauren Bacall, Humphrey Bogart had 'emotional affairs' but remained 'devoted to each other': author

Lauren Bacall and Humphry Bogart’s passionate romance is still recognized as one of Hollywood’s most legendary love stories, but it wasn’t always marital bliss.

Author William J. Mann has written a book on the power couple that was recently published, "Bogie & Bacall: The Surprising True Story of Hollywood’s Greatest Love Affair." In it, he alleged that the pair had once been "emotionally unfaithful" to each other, their significant age gap being a major factor.

In painting an honest portrayal of the couple's marriage, the Hollywood historian spoke to several surviving insiders and had access to never-before-seen documents.

Bacall, one of the last stars from Hollywood’s golden era, died in 2014 at age 89.

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"When we talk about great love stories, we think of them in fairytale terms," Mann told Fox News Digital. "You know, ‘And they lived happily ever after,’ as if there weren’t going to be challenges, there weren’t going to be conflicts. When you make a life with someone, it’s about learning how to compromise, learning how to find a way forward together despite what are going to be some differences."

"And they did have their differences," he shared. "Especially in the beginning when Bacall was struggling to be more than just Mrs. Bogart. The relationship was romantic. It was loving, it was committed. But it was not always emotionally faithful."

"I think… they were emotional relationships, emotional affairs," Mann claimed. "You can be emotionally unfaithful to your spouse."

Bacall, a fashion model, moved to Hollywood from New York when she was 19. She achieved immediate fame in 1944 with one scene in her first film, "To Have and Have Not." Leaving Bogart’s hotel room, the starlet purred, "You know how to whistle, don’t you, Steve? You just put your lips together and blow."

Bogart, who was married to his third wife, actress Mayo Methot, became Bacall’s lover when cameras stopped rolling. He was 25 years older than her.

"Bogie became her champion, her protector," Mann explained. "And I think that sense of him needing to take care of her and protect her really endeared her to him. … And their feelings quickly turned into love."

The blossoming romance "terrified" Bacall, he said. Such a scandal would destroy her career before it even started.

"It was known at that point that Bogart’s marriage was disintegrating," said Mann. "They were known as the ‘Battling Bogarts.’ But, at the same time, Bacall wanted to make sure the public wouldn’t blame her or wouldn’t see her as a femme fatale. Bogie was also very concerned. He didn’t want to lose his position in Hollywood, but he also didn’t want to lose her. In the beginning, there was a lot of nervousness. … But they were yearning to be together."

Bogart returned to Methot several times before realizing his marriage couldn’t be saved. In 1945, Bogart married Bacall. He was 45, and she was 20.

According to Mann, it didn’t take long for their marriage to be tested.

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In 1952, the couple became supporters of Adlai Stevenson during the 1952 presidential election. The governor of Illinois was running as a Democrat opposite Republican Dwight D. Eisenhower.

"Bacall was always a liberal Democrat," Mann explained. "Bogie was originally for Dwight Eisenhower [but] eventually came over to Stevenson’s side as well. … And she got campaign fever. Many people who’ve been in political campaigns understand that … you get this adrenaline rush. It was nothing she had ever experienced before. And because I think she thought she was working for … a higher purpose, this took on even greater meaning for her than making a movie."

"She comes out and says in her memoir, ‘I was far away from Bogie. All I was thinking about was Stevenson,'" Mann shared. "And in Bogie’s papers, I found notes from him to [director] John Huston where he’s clearly uncomfortable by his wife’s infatuation with this political candidate. And it got very intense."

In her memoir, Bacall wrote, "At every speech from the beginning — every platform, breakfast, lunch — Stevenson would catch my eye and wave and smile at me. To my fantasizing mind, he seemed so vulnerable."

"Bogie said he had a funny idea for a cartoon," the mother of two shared. "He’d be standing at our front door with a child on each side and rain falling heavily and [my son] Stephen would say, ‘Daddy, where’s Mommy?’ Bogie, looking sadly into space, would reply, ‘With Adlai.’ It was a funny idea and I laughed, but Bogie knew I had been deeply affected by Stevenson and, for that matter, he had too."

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Mann insisted in his book that Bacall and Stevenson "had become quite close" and "she was rarely far from his side, with Bogie somewhere in the background." He stressed that the relationship was never physical, but "it was definitely an affair of the heart."

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"She loved Bogie," said Mann. "But Stevenson was awakening some part of herself that she had never known before. The relationship continued through the end of the campaign. He lost in a landslide, and she was devastated. She tried to keep in touch with him, but it became increasingly difficult. My take on it, looking back all these years, is that she was more into him than he was into her. … She finally realizes [this] and retreats. But in many ways, I think it was the most intense, emotional and intellectually stimulating relationship of her life."

In her memoir, Bacall vividly remembered when Stevenson lost.

"I adored Adlai Stevenson, I supposed I even worshipped him," she wrote. "He instilled that feeling in many — loyalty, adulation. He brought out the best in me, or at least I thought he did. He made me feel I knew more than I actually did, that I was valuable. He broadened my horizons, made me more aware of human dignity and the plight of people everywhere. Until Adlai Stevenson, I was a perfectly happy woman with a husband whom I loved — a beautiful son and daughter — not a care in the world. His entrance into my life shook me up completely."

"In my usual way, I romanticized," she continued. "He needed a wife, obviously … but he needed someone to share his life with. I fantasized that I would be a long-distance partner — a pen pal — a good friend whom he could feel free to talk to about anything. A sympathetic, non-judging ear. It took me a long time to dissect my feelings, but, at the moment, I felt a combination of hero worship and slight infatuation. This campaign had disrupted my life completely."

Mann says Bogart had his own emotional affair.

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"I was very fortunate to speak with the surviving partner of Verita Thompson," he explained. "She was a wigmaker in Hollywood. … She made Bogie’s wigs for him because he was starting to lose his hair very early. Before Bacall, they began an affair while he was still married to his third wife. It was an incredibly close and loving relationship. They weren’t that far apart in age. … They both liked to drink — they could hold their liquor. They loved to sail. They had a lot in common."

According to Mann, Thompson, who also went by Vera, believed Bogart would divorce Methot and propose because "they had talked about getting married." But when he quickly moved on to his much younger, more glamorous co-star, she was "devastated."

"They eventually reconnected," said Mann. "And I think, at that point, the relationship was most likely emotional. … I think especially as Bacall was finding her own world, her own life, her own friends, people like Adlai, Bogie turned more and more to Verita. They would go sailing together on his yacht. … She began coming to the house. She would trim his children’s hair. She was part of the family in many ways. Bacall knew about her. I don’t think she was ever fully comfortable with her, but she knew that relationship was very important to Bogie."

"But these relationships never threatened the primary bond between husband and wife," Mann insisted.

Bacall and Bogart remained devoted to each other, especially as the actor battled cancer. The actress became a doting caregiver.

"She's sitting with him in the hospital, and his stitches are coming undone," said Mann. "She's trying to hold the stitches together on his abdomen. She sleeps with him when he's about 80 pounds, because he tells her, 'Don't leave me tonight.' ... Of course, she doesn't sleep all night. She's awake. You don't do that if you don't really love somebody. Even with the emotional indiscretions ... those last several months of Bogie's life prove how much she loved him."

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Bogart died in 1957 at age 57.

"I fairly often have thought how lucky I was," Bacall reflected to Vanity Fair in 2011. "I knew everybody because I was married to Bogie, and that 25-year difference was the most fantastic thing for me to have in my life."

The Associated Press contributed to this report.