For decades, Kathleen Turner maintained that she and Michael Douglas never had an affair while filming “Romancing the Stone” — a story Douglas now admits was a lie.

In an excerpt from his upcoming “One Helluva Ride” memoir, shared by People on Friday, the 82-year-old actor says that the on-screen duo also romanced each other off-screen.

Turner repeated their carefully constructed cover story — which Douglas says was intended to protect his then-wife, Diandra Luker, and their son, Cameron — numerous times over the years.

In 2008, Turner, 72, was a guest on “Larry King Live,” when a caller asked whether she and Douglas had “a relationship outside of working.”

“Well, let me — only a good friendship,” she replied, adding that she had become “rather attracted” to the Oscar winner while making the 1984 rom-com, but his wife Diandra’s arrival “put an end to that.”

“We just became extremely good friends,” the “Peggy Sue Got Married” star added.

Ten years later, Turner was again asked about an on-set romance on “Good Morning America.”

“I wanted to. I thought we were falling madly in love…” Turner said, noting that nothing happened because Diandra arrived in Mexico and made clear that she and Douglas were still married.

The same year, Turner confessed on a British chat show to feeling “rather romantic towards Michael,” but claimed that ended once Luker arrived. “So that was that. You don’t mess with other women’s marriages.”

In 2021, Turner was asked yet again about a Douglas dalliance.

“Heavens, I certainly had a crush on Michael during ‘Romancing.’” Turner told the Los Angeles Times.

She said Douglas had told her he was separated, so “it seemed as though … we could have a relationship,” but maintained that Luker’s arrival “killed that.”

Turner admitted she had been “knocked out by him for a while.”

That same year, she continued to maintain that their attraction never became an affair.

“Oh, I was yearning, babe, but he was still married…” she told People, characterizing their chemistry as “wonderful sexual tension.”

In 2023, the “Who Framed Jessica Rabbit?” star refused to say exactly how close she and Douglas really got during filming.

“None of your business,” she cheekily replied.

At the time of filming, the “Wall Street” star was married to Luker, with whom he shares son Cameron, but the couple were separated and, according to Douglas, “both having extramarital affairs.”

“We found each other first as friends, then as co-stars and finally as lovers. Following an exhausting day of shooting in the jungle … I would sneak into her hotel room after everybody was asleep,” he wrote.

However, the affair ended abruptly when Luker and Cameron visited the set, and she confronted Turner.

The conversation “gave Kathleen pause” because “she didn’t want to interfere,” leading Turner and Douglas to end their affair.

“I went back to Diandra,” Douglas wrote. “I did it for Cameron, but we shouldn’t have gotten back together. After that first split, it was never the same between us ever again.”

Douglas said he and Turner then concocted a false narrative to “protect” Luker and Cameron.

“Yes, we confessed, we had amazing chemistry,” he wrote. “Yes, we were both, as Kathleen said, ‘terrible flirts,’ and yes, we were both tempted, but nothing ever happened between us. That was a lie.”

Douglas and Luker divorced in 2000. He later married Catherine Zeta-Jones, with whom he shares son Dylan, 26, and daughter Carys, 23.

Turner married Jay Weiss in 1984; they divorced in 2007 and share daughter Rachel, 38.

Douglas and Turner reunited on screen for 1985’s “The Jewel of the Nile,” 1989’s “The War of the Roses” and, decades later, Netflix’s “The Kominsky Method.”