Michael Douglas’s first memoir, One Helluva Ride, is published on October 6. It contains a major revelation about his past.

Douglas reveals that he had a secret romance with his Romancing the Stone co-star Kathleen Turner. The relationship began in Mexico in 1984 during filming. The two had denied the romance for decades.

Douglas writes that Turner consented to him sharing the story. Turner told People magazine: “Good heavens what a fuss about something 40 years ago! I love Michael and I look forward to enjoying the book.”

The memoir also addresses a long-standing rumor. Douglas denies he ever went to rehab for sex addiction. He says he entered rehab in 1994 for overwork and alcohol abuse.

Douglas won his first Oscar at 31 as producer of One Flew Over the Cuckoo’s Nest. He won Best Actor for playing Gordon Gekko in Wall Street.

He married Catherine Zeta-Jones in 2000. The couple recently celebrated their 25th wedding anniversary.