John Lennon could be ‘cruel,’ Yoko Ono called daily at 4 a.m. — and other secrets from one of their closest confidants

John Lennon once allowed Los Angeles-based radio DJ Elliot Mintz to preview his new album – a move aimed at boosting his career.

“Some Time in New York City” was the hotly anticipated collaboration between Lennon and Yoko Ono set for release in 1972, less than two years after The Beatles had split.

When Mintz got the early copy, the songs were not even printed on the sleeve or label, but he was champing at the bit to be the first to play it.

Shockingly, the gift wound up costing him his job, which, in turn, launched him on a wild ride no one could have predicted.

As explained in his new memoir, “We All Shine On: John, Yoko, and Me” (Dutton, out today), the record’s opening cut is “Woman is the N—-r of the World,” a song where the N-word is featured prominently. Mintz’s bosses at the station were unimpressed and promptly canned him.

He told as much to Lennon and Ono. “They found the story amusing,” Mintz told The Post. “Then, John asked what I was going to do. I told them I guess I’ll be looking for a job. And he said, ‘Well, tomorrow, we’re heading off to San Francisco. Why don’t you join us?’” 

Mintz said yes – the trip was for Lennon and Ono to see an herbal specialist who would mysteriously help Ono to conceive a child – and this began an unconventional friendship. 

“They were in the process of kicking methadone habits,” said Mintz, now 79. “The two of them occasionally took heroin … and they found themselves in a spiral. They never shot [injected] anything. They snorted it. It led to them seeking help, they got methadone and became hooked on that drug.”

Mintz, arguably, became hooked on Lennon and Ono. And, perhaps, they did on him too. John and Yoko sent Mintz a collage that doubled as a birthday card in the early 1970s, they had him join in on a trip to Japan (where Mintz ate turtle soup out of the turtle’s shell) and he hung out in New York recording studio the Hit Factory with the couple as they recorded “Double Fantasy.”

Yoko regularly called him at 4:00 in the morning for long conversations about whatever was going on in her world. It hampered Mintz’s sex life, as he recalled a woman who was spending the night and did not take kindly to the rude awakening middle-of-the-night call from a mystery woman. Mintz was sworn to secrecy about his A-list friendship and did not blab to his conquest.

“She packed her bags and called a cab,” he said. “The next day I realized that concessions would have to be made. I wasn’t going to be able to conduct a personal life the way I had.”

In fact, he made it easier for Lennon and Ono to intrude. “I wound up installing a hotline, with a number that would only be for John and Yoko,” said Mintz. “I’m an insomniac, Yoko woke up at 7 a.m. in New York [which was 4:00 in Los Angeles], and they liked the idea that they could call that number any time, day or night, and I would be awake. They could share their innermost secrets. They got used to it and, of course, I got used to them.”

Among the secrets which Mintz kept: Lennon phoning in 1972 to confess a sexual infidelity. He and Ono had been attending a party in the home of political radical turned Wall Street investor Jerry Rubin. With the party was in full swing, Lennon slipped off to a spare bedroom and had noisy sex with one of the female guests. It was loud enough to prompt someone to turn up the volume on a Dylan record in an attempt to drown it out. Ono, of course, had actually heard everything. 

They both unloaded their sides of the story to Mintz who had to juggle his relationship with the couple while maintaining various jobs in radio and television. “Sometimes [dealing with them] became an intrusion,” said Mintz. “At what point do you rein it back in? Keep in mind that I never was paid.”

However, things only got wilder for Mintz after Lennon appeared on his home turf, during the rocker’s so-called “Lost Weekend,” which was actually an 18 month long binge of sex, drugs and booze from September 1973 until 1975.

After what Mintz calls Lennon’s “indiscretion” at Rubin’s place, Ono had exiled him to Los Angeles with their assistant May Pang.

While it’s widely believed that Ono hand-selected Pang to be a surrogate girlfriend for Lennon, Mintz remembers it differently. Yoko, he said, “selected a then-assistant to accompany him and basically look after his basic needs.

“She did, very competently, and their relationship turned into something more than a separated husband and assistant.”

In fact, it became a full-blown love affair. 

But, as Mintz learned the hard way, Pang was not the only woman with whom Lennon strayed. “He called, woke me up and told me to go to an address,” Mintz recalled, explaining that he honored the request, rolled up to a house he’d never been to before and found Lennon in bed alone and under the sheets as a woman in a bathrobe waited in the adjacent room. “John just looked at me and said, ‘Get rid of her.’”

Mintz did as he was told but he didn’t like it. And it generated one of the few instances in which he felt compelled to stand up to Lennon. He told him he was the wrong man for the job and he hoped not to be asked to do it again. 

“John got angry at that,” said Mintz. “He shouted at me and said, ‘I’m going to ask you to do anything I feel like asking you.’”

Mintz split the scene and got home to his hotline ringing. It was Lennon, who had now cooled-off. “Look,” he told Mintz, “I’m sorry I shouted at you. But you just can’t tell me what I can or cannot say.”

Lennon, Mintz rationalizes today, “had a big mouth and did not keep his emotions secret. He did not want anybody limiting his self-expression.”

In the case of Mintz, however, Lennon did it at his own risk, as he had a secret connection over him. “Yoko and I talked every night,” said Mintz. “When they had their separation, I told them that I wouldn’t keep secrets from one or the other” – though in this instance he did, not bringing up the dalliance and instead talking to Ono about mundanities like her upcoming gallery opening and the state of her mahjong game.

But that was not the final drubbing from Lennon. 

Following a night of extreme inebriation, Lennon went so wild that the bodyguards working for Phil Spector – with whom Lennon was recording an album later titled “Rock ‘N’ Roll” – tied him to a chair. 

Mintz was called in to calm down Lennon and unrestrain him. “He looked at me and said, ‘What are you doing here?’” recalled Mintz. “Then he hurled an epithet at me. I don’t repeat it in the book and I just can’t repeat it to you now. It was really mean and it scarred me.”

Nevertheless, on the dark night of December 8, 1980, when Lennon was murdered by a maniac fan’s bullet, Mintz hopped on a red eye from LA to New York and dropped into the Dakota building, unbidden, to comfort Yoko Ono. When she needed somebody to sort through Lennon’s belongings, he took on the task. 

Among the many pairs of wire framed glasses and musical instruments, Mintz found an unsent letter. It was in a sealed envelope that was addressed to him. He did what for some would be unthinkable. “I did not open the letter,” he said. “That envelope did not belong to me.  I thought about it. I’ve wondered about it. But it was not my place to open that envelope.”

Looking back on everything, considering all that he did for Lennon and Ono, with no financial recompense for his trouble, why does Mintz think he hung in there with them for so long? “Love,” said Mintz. “It’s love that I received from those two people. They completed me.”