Michael Douglas: Why I refused Letterman for 18 years

Michael Douglas said no to David Letterman for 18 straight years, and he is finally explaining why.

In his memoir “One Helluva Ride,” which Page Six reports on, the 82-year-old actor writes that Letterman crossed a line during his final appearance on “Late Show.”

The trouble started when Letterman aired a commercial filmed by Douglas’ late mother, Diana Dill, during a segment — “without warning,” Douglas says. The host then “started grilling” him about it.

“It felt like he was making fun of my mother,” Douglas writes.

The “Wall Street” star says the experience left him convinced Letterman “had a real nasty sense of humor.” After that, whenever producers asked him back, Douglas writes, “I always refused.”

“I said no for 18 straight years,” he writes. “Dave wrote me personal letters to apologize, but my feelings didn’t change. He had crossed a line.”

“It felt like he was making fun of my mother.”

Douglas writes that he ultimately decided to “bury the hatchet” after his 2010 cancer diagnosis. When he finally returned to the show, Letterman was “respectful” and asked “sincere and sympathetic questions.”

“It felt so nice to clear the air with Dave, and for the first time I felt like life is too short to hold on to feuds,” Douglas writes. “Letting go felt like it was more of a favor to myself than to Dave. Those grudges were a weight I carried, and I was done with revenge.”

The memoir also includes revelations about an affair with Jeanne Tripplehorn, his dramatic weight loss from cancer, and the moment he told now-wife Catherine Zeta-Jones on their first date, “I’m going to be the father of your children.” She walked out, but they married two years later.

“One Helluva Ride” hit bookshelves Tuesday.