Michael Douglas and Costar Kathleen Turner Were Secret 'Lovers,' Actor Claims in His Memoir: 'We Were Immediately Attracted to Each Other'

Michael Douglas came clean about a decades-long secret.

In his new memoir, One Helluva Ride, the 82-year-old recalled how he and his Romancing the Stone costar Kathleen Turner, 72, fell for each other while filming the 1984 blockbuster in Mexico.

At the time, he was separated from his then-wife, Diandra Douglas, with whom he shares his son Cameron.

Michael, who was a producer on the action-comedy, initially wanted Debra Winger to play the leading lady, but when that didn't end up working out, Kathleen was given the role.

In an excerpt from his memoir, the Basic Instinct actor said, "Kathleen was smart, funny, and s--- with a deep, sultry voice that became her signature. I instantly liked her, and we were immediately attracted to each other."

"Things at home were in a bad place. Diandra and I were both having extramarital affairs," he revealed. "I never asked Diandra to change who she was, but having found out who I was after she fell in love with me and married me, Diandra constantly asked me to change. It created enormous problems between us...I left for Mexico still technically married, but separated."

The public speculated for years that Michael and Kathleen had feelings for each other; however, the pair denied the rumors for decades.

"The chemistry I had with Kathleen Turner was so strong, audiences have been certain for years that we were in a relationship together while making the film. We both denied it through Romancing the Stone, Jewel of the Nile, War of the Roses, and even while doing press a few years ago for The Kominsky Method," he continued.

"The official story went as follows: Yes, we confessed, we had amazing chemistry. Yes, we were both, as Kathleen said, 'terrible flirts,' and yes, we were both tempted, but nothing ever happened between us," the star wrote. "That was a lie."

"Kathleen and I never hit a rough spot. We found each other first as friends, then as co-stars, and finally as lovers. Following an exhausting day of shooting in the jungle, we’d go out and have a meal, or head out with the group and afterward I would sneak into her hotel room after everybody was asleep," Michael confessed.

He went on, "There were no cameras in elevators, no assistants using cell phones to take pictures. As Jack and Joan were falling in love, Kathleen and I were keeping the chemistry alive. We kept our involvement hidden. Even [director] Bob [Zemeckis] and [costar] Danny [DeVito] were unaware."

"The magic spell of the set was broken when Diandra brought Cameron down to Mexico...Diandra grew suspicious...At some point, she was alone with Kathleen and made it clear to her that we were still married," he shared. "Her view of the terms of our separation was different from mine. This gave Kathleen pause...After that visit, Kathleen and I ended things, and I went back to Diandra."