Beatle Paul McCartney helped John Lennon win back Yoko Ono after star cheated with another woman: pal

John Lennon and Yoko Ono’s marriage wasn’t always peace and love.

From late 1973 through 1974, Lennon embarked on his "Lost Weekend" in Los Angeles while being separated from his wife. Ono had banished the singer/songwriter from their home after he had had "loud, raucous sex" with another woman at a party.

While Lennon was eager to return to Ono, she was wary about him coming home. That’s when she got by with a little help from an unlikely Beatle.

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Paul McCartney (right) gave John Lennon (center) advice on how to win back his wife Yoko Ono (left). (Michael Webb/Keystone/Getty Images)

"There was a time when Sir Paul McCartney offered Yoko his willingness to speak to John in Los Angeles about the separation," the couple’s pal, Elliot Mintz, told Fox News Digital. "She seemed grateful for that invitation."

The former Los Angeles radio and TV announcer, who met the couple in the early ‘70s, has written a new memoir, "We All Shine On: John, Yoko, & Me," with the blessing of their son, Sean Lennon. In the book, he describes how McCartney gave a heartbroken Lennon sound advice on how to win back his love.

"Paul came out here, he had a meeting with John," said Mintz. "His advice to him was, ‘You can’t just say that you’ve changed. You have to show it. You have to prove it. It would be like dating her again. You have to bring her flowers, you have to take her out for dinners. You have to show her how important she is to you in your world.’"

Elliot Mintz said that Yoko Ono appreciated Paul McCartney (right) wanting to help his friend and former bandmate. (Getty Images)

"There was a time when Sir Paul McCartney offered Yoko his willingness to speak to John in Los Angeles about the separation. She seemed grateful for that invitation."

— Elliot Mintz

Mintz said that Lennon took McCartney’s advice "to heart." It worked.

"Yoko accepted him back in their home, and they resumed their relationship," Mintz explained. "It was not fun to be around John during the lost weekend. Keep in mind that John had never really been a bachelor. From his days at Liverpool, he had always been married. So this was a time when he sowed wild oats. Yoko sent him out here [in Los Angeles] while they had problems in their marriage to find himself."

"Actually, he lost himself during the lost weekend and climbed the ladder back to her heart," Mintz reflected.

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John Lennon embarked on an affair with his assistant, May Pang. (Art Zelin/Getty Images)

During the couple’s separation, their assistant May Pang said that Ono asked her to date Lennon in hopes of keeping him company. Lennon and Pang embarked on a whirlwind 18-month affair.

"I’ve met her on several occasions," said Mintz about Pang. "She’s an articulate woman who was the ideal companion to be sent out to Los Angeles to be with John. She didn’t smoke, she didn’t drink, and she truly had his interests at heart. I believe that to be true. I have good feelings about her."

"She tends to portray the lost weekend as a time of great creativity for John, a time of intense love between the two of them," Mintz continued. "I just saw it a little differently. I don’t doubt for a moment that May fell in love with John for all the right reasons. I would never question or second-guess a woman’s passions in that area. And of course, what they shared will remain between the two of them. But I just saw the timeframe differently than she did."

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Mintz said the lost weekend, a reference to the 1945 Billy Wilder film, was "the most depressing two years or so that John ever experienced."

"John went completely off the rails," said Mintz. "He filled most of his time in LA under the influence of substances, staying up all night, not producing a lot of anything. When I spoke with him, he sounded more depressed than he sounded happy."

During their conversations, Lennon pleaded that he was ready to come back to Ono, Mintz claimed.

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Elliot Mintz (right) was friends with John Lennon and Yoko Ono for nearly a decade. (Courtesy of Elliot Mintz )

"We spoke about how he was ready to return to Yoko," said Mintz. "He called Yoko ‘Mother,’ and he would say to me, ‘Please tell Mother that I’m ready to come back.' Dutifully, at the end of each day, whenever we spoke, Yoko would say, ‘How’s he doing?’ I said, ‘Look, he really feels like he cleaned up his act and he’s ready to come home.' And for a very long time, Yoko just said to me, ‘No, he isn’t.’"

Mintz’s book described how, in 1972, Lennon got drunk while watching the presidential election results between Richard Nixon and George McGovern at anti-war activist Jerry Rubin’s New York City apartment. Lennon and Ono were guests at the party being held there.

After Lennon’s drinking got heavier, he had sex with another woman. Mintz said Ono "could clearly hear them going at it." 

One party guest attempted to drown out the noise by playing a Bob Dylan ballad. It didn’t work.

Elliot Mintz told Fox News Digital that John Lennon was desperate to come back to Yoko Ono during their separation. (Vinnie Zuffante/Getty Images)

"Throughout it all, Yoko sat on the sofa, in stunned, mortified silence, as other guests began awkwardly getting up to leave — until they realized that their coats were in the bedroom where John was having sex," Mintz wrote.

Mintz said that the next morning, he received a call from a very hungover Lennon. He had slept on the sofa that night.

"Things like that happen," Lennon argued. "A bloke cheats on his wife… If I weren’t famous, nobody would care."

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Elliot Mintz's memoir is out now. (Dutton)

Mintz wrote that Ono felt differently.

"I can forgive him. But I don’t know if I can forget what happened," she told him. "I don’t know if it will ever be the same."

After their separation, Lennon and Ono renewed their vows in 1975. Later that year, they welcomed their son, Sean Lennon.

John Lennon is seen here with Yoko Ono and their son Sean Lennon outside their New York City apartment building, circa 1977. (Vinnie Zuffante/Getty Images)

"One of the most popular theories is that, from 1975 to 1980, John turned into a recluse and that Yoko had him locked away in their bedroom, where he grew into an almost Howard Hughes figure who was constantly high," Mintz told Fox News Digital. "He was actually in the business of raising his son."

"We made a joke about it," Mintz shared. "Even during the five years that he wasn’t making music, he was creative. . . . Another myth that has been perpetrated is that Yoko hired a hypnotist to put John under the influence to return to her at [their apartment building] The Dakota after their separation. It’s not true. John knew I had seen a hypnotist. He remembered my experience. He said, ‘I’ve kicked about everything, but I can't quit cigarettes. Do you think that hypnotist guy could do it?’"

Japanese-born artist and musician Yoko Ono and British musician and artist John Lennon (1940-1980) sit together on a bed, December 1968. (Photo by Susan Wood/Getty Images) (Getty Images)

"I hired the hypnotist to fly out from Los Angeles to New York," Mintz continued. "When their session was over, John called me. I said, ‘How did it go?’ He said that he liked the guy, but he didn’t feel like he was ever under. He didn’t feel like he was hypnotized. . . . John smoked until the end of his life."

In November 1980, Lennon released his final album, "Double Fantasy." In December of that year, Lennon was gunned down outside his New York City apartment. He was 40.

"John Lennon was very centered and very articulate," said Mintz about their friendship. "But when we got to know each other more, I also recognized his vulnerabilities, his jealousies, his propensity for anger. I realized he was not all love and peace, peace and love. He embraced those concepts and had an allegiance to them. [But] he didn't always practice them. I became aware of his humanity."

"Yoko had a very stoic reputation - humorless," Mintz continued. "She always carried that albatross of being the person who broke up the Beatles, which she didn't. I recognized her vulnerabilities in her as well. It made so much sense that the two of them had found each other."