In our 60-year obsession with the Beatles, the group’s women have always played a compelling part. Ringo’s long-lasting marriage to “Caveman” co-star Barbara Bach; the George/Pattie Boyd/Eric Clapton triangle; Paul’s heart-tugging romance with Linda and, of course, John and Yoko.

But perhaps the most enigmatic of all Beatle women is May Pang, John Lennon’s lover when he was on the outs with Yoko Ono. What Lennon had famously called his “Lost Weekend” in 1973 actually lasted 18 months. It was also one of Lennon’s most creative and successful post-Beatles periods with the release of the “Mind Games” and “Walls and Bridges” albums, and May Pang was in the middle of everything. Christmas cards were signed John and May. There was talk of buying a house in Montauk.

The love affair was at its pinnacle when it was suddenly brought to a halt. The one who pushed the two together, said Pang, Yoko Ono herself, had seen enough.

The private photographs Pang took during those wild 18 months, mostly in New York and Los Angeles, is at the heart of a touring exhibition coming to R. Michelson Galleries Friday, Sept. 27, through Sunday, Sept. 29: “Lost Weekend: The photography of May Pang,” with Pang herself on-hand to answer questions the whole time.

“The burning question is ‘What was he like?’” said Pang from her New York home last week. She prefers to think of that time as what were we like. “This is John, the way I saw him. He’s not posing. I want people to know my story.”

Pang, 73, has published two books about her life with Lennon and the tour coincides with the digital release of a documentary on Lennon and Pang: “Lost Weekend: A Love story,” which traces Pang’s rock ’n’ roll childhood in New York’s Spanish Harlem, to her boldly talking her way into a job at Apple Records at age 19, to her serving as personal assistant, production coordinator and all-around gofer for John Lennon and Yoko Ono when they moved from London to New York.

Pang had to pinch herself at times — 20 years old with witness to history. “It was a long way from Spanish Harlem,” she said. “Every day was a crazy adventure. I heard ‘Imagine’ for the first time ever, John’s message for a better world.”

She worked on John and Yoko’s avant-garde projects and sang with them on the Christmas classic “Happy Xmas (War Is Over)” along with the Harlem Community Choir.

Yoko does not come off sympathetically in the documentary, portrayed as a master manipulator of Lennon. Pang said that Julian, Lennon’s son from his first marriage, called the house repeatedly but Yoko wouldn’t let the call go through. “I had to lie to both John and Julian,” said Pang sadly.

But after working for the couple for three years, out of nowhere comes Ono’s suggestion, err, demand that Pang start dating Lennon.

Why?

“I have no idea,” said Pang. “They were having problems, fighting … I was stunned. ‘I can’t do this!’ I said. ‘He’s my boss, he’s your husband!’ ‘DO it!’ Yoko said, ‘I’ll take care of everything.’”

“In the end, he pursued me,” Pang said. ‘I don’t know what’s going on here,’ I told him. ‘Neither do I,’ he said. I wasn’t going for it. But John Lennon charmed the pants off me. Then we kissed. Then we made love. I asked, ‘What does this mean?’ he said, ‘I don’t know.’”

“I showed John the real New York,” said Pang. “I said ‘Let’s go on a bus ride.’ He says: ‘Uh, did you actually say let’s go on a bus ride?’ But he loved it. He enjoyed seeing what everybody else sees.”

“Then I’d see Yoko the next morning at work. She thought it would be a couple of weeks and he’d be crawling back. And when it didn’t it freaked her out,” Pang said.

“She asked for a divorce and he said yes and then she said the stars weren’t right.”

In September 1973, John Lennon and May Pang moved to LA, “to get away from Yoko,” she said. “Ringo was out there, every day was something new. We lived like giddy teenagers.”

The song “Surprise, Surprise (Sweet bird of Paradox)” with its lyric “I was wonderin’ how long this could go on, on and on?” is all about Pang and Lennon.

And May Pang took lots of pictures. “I’d be playing around with my camera. John liked my eye, always egging me to do more.”

Some of these shots are in-the-moment iconic like the three-foot canvas of Lennon’s signing of the document officially dissolving the Beatles, one of many for sale at the exhibit. His mood? “Finally it’s done,” said Pang.

What followed were barbs in the form of songs from John Lennon and Paul McCartney directed at each other, a friendship destroyed.

But maybe not. Pang was instrumental in getting John reconnected with Julian, and she forged a lifelong friendship with the boy’s mother, Cynthia, John Lennon’s first wife, who died in 2015.

“May had a great relationship with Mum,” said Julian Lennon, who speaks of his father’s time with May Pang as the happiest he’d ever seen him.

To live and die in LA

Lennon quickly began carousing with the Hollywood Vampires, the celebrity drinking club of Alice Cooper, Keith Moon, Micky Dolenz, Harry Nilsson, Ringo Starr fame, many of whom moved into a rented house in Santa Monica with Lennon and Pang while recording Nilsson’s album “Pussy Cats.”

As one who didn’t drink or use drugs, Pang was the perfect hall monitor for such party carnivores. “They’d get going and didn’t know when to stop,” she said. “Even though I was the youngest, I was the oldest. When I said ‘no!’ — they knew I meant business.”

She also saw Lennon at his worst, during the boozy, chaotic sessions for his Phil Spector-produced “Rock ’n’ Roll” album, which had Spector — the future convicted murderer — pointing a gun at Lennon and discharging the weapon in the studio, causing the ex-Beatle to explode in rage, smashing things at home and shoving Pang.

He failed to apologize to Pang the next day, only saying “I don’t think it’s gonna work.”

But back in New York, the couple were reportedly at their happiest, watching a UFO from their terrace on East 52nd street, whilst naked. The classic Bob Gruen shot of Lennon on that roof wearing his New York City t-shirt with the cut-off sleeves — Pang took the picture of the picture being taken.

But their first visitors in NYC were Paul and Linda McCartney. The doorman calls up: “We got a Paul and Linda down here!”

“John says, ‘What should I do?’ I said, ‘Send ‘em up — they’re your friends!’”

“Five years of anger and animosity melted away,” said Pang, who took the only known photos of the jam session that followed, the single time John and Paul played together post-Beatles.

“They talked about hooking up in New Orleans, talked about writing together again,” said Pang. “Had we gone down there and surprised Paul and Linda, it might have made history. Of course, it never happened.”

The night before the trip, Yoko Ono reached out to John Lennon.

Got a light?

Amid the activism, search for meaning and incredible music of the 1960s and ’70s, cigarettes were attached to every waking moment.

The habit took its toll on Lennon. “He was losing his breath,” said Pang, “having trouble sustaining notes; those French cigarettes he’d smoked forever.”

“Then Yoko calls: ‘Guess what I got. I found this hypnotist. I quit smoking!’”

“John cries, ‘You what?!’ Yoko had been a chain smoker all her life. He runs over there. They give him this tea and he keeps throwing up.”

Pang was told John was unavailable when she called. The next time she sees Lennon he seems confused, disconnected, Pang said, almost as if he’d been brainwashed. “He turns to go, I say ‘Where are you going?’ ‘Home,’ he says. I say ‘Home is this way.’ ‘Yoko has allowed me to come home,’ he says.”

“Allowed?”

The Lost Weekend was over. John Lennon’s next weekend, with Yoko Ono, was to last until the end of his life.

“We saw each other on and off for the next five years, and often were intimate,” Pang admitted.

And then he was gone forever, at the hands of yet another assassin with three names.

“I was at a friend’s house on the Upper West Side. We heard it on the radio. I freaked out! I gotta run home. I come in the door and the phone’s ringing and it’s Ringo’s secretary and she wants the name of the hospital and I say it’s no use, he’s gone. And she cries ‘What’s wrong with your bloody country?!’”

“You never get over it,” said Pang.

As for John referring to their time as “lost,” Pang shrugged, “You take it in stride. He first used the lost weekend thing in a 1980 interview. He called me and said ‘I just want you to know it’s not about us. One day the world will know about us.’”

“I didn’t think it would take 50 years,” said Pang with a laugh.

“In the end, he loved Cynthia, he loved Yoko, and yes, he loved me.”