Photo: Rich Fury/Getty

Harry Hamlin (L) and Lisa Rinna attend the Amazon Prime Video post Emmy Awards party at Cecconi’s on September 17, 2018 in West Hollywood, California

Harry Hamlinknows a thing or two about maintaining a healthy marriage.

In this week’s issue of PEOPLE, the actor, 71, opens up about his 25-year marriage toReal Housewives of Beverly HillsstarLisa Rinna, the secret to their lasting relationship and the lessons he learned from his previous marriages.

“I’m different from a lot of men in my generation because I did not play the field,” says Hamlin, who was previously married to Laura Johnson andNicollette Sheridanbefore marrying Rinna in 1997. “The number of people with whom I’ve been intimate is not very many — I marry them, mostly. Probably the first couple [of marriages] were me trying to work stuff out because they had characteristics that were similar to my mother.”

“Having a degree in psychology allows me to go back and research from this book, which is very helpful when you’re trying to figure out who the f— you are,” Hamlin says, as he pullsDiagnostic and Statistical Manual of Mental Disordersfrom his bookshelf.

“I think a lot of people end up trying to work s— out with their lovers,” he adds. “Breaking the cycle is not easy. Having not married my mother the third time, then comes the challenge: How do you make that friendship and relationship work both romantically and platonically?”

Harry Hamlin and Lisa Rinna.Roxanne McCann/Getty

BEVERLY HILLS, CA - MARCH 29: Actors Lisa Rinna and Harry Hamlin pose for a photo after their wedding at their home on March 29, 1997 in Beverly Hills, California. (Photo by Roxanne McCann/Getty Images)

Hamlin ultimately figured out how to make things work with Rinna, 59, with whom he shares daughters Delilah, 24, and Amelia, 21. Last March, theymarked 25 years of marriage.

“‘Happy wife, happy life’ really is my mantra,” Hamlin says. “And it works. We listen to each other, and we’re not clingy. She does what she wants, so I can do what I want.”

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Gregg DeGuire/FilmMagic

Amelia Gray Hamlin, Harry Hamlin, Lisa Rinna, and Delilah Belle Hamlin

Hamlin — who is also dad to 42-year-old son Dimitri with former girlfriend Ursula Andress — has previously spoke about his successful marriage,telling PEOPLE in February: “[The secret is] being diametrically opposite.”

“I like going up to the mountains, and her idea of camping is anything below the 10th floor of the Four Seasons,” he explained.

Hamlin and Rinna also admitted at the time that their road to happiness had its early bumps.

Hamlin added, “So I called her up and I said, ‘Do you want to come to dinner at this Italian restaurant?’ and she said, ‘When?’ I said, ‘Well, how about in an hour?’ And I hadn’t talked to her in months. And, she showed up and broke all the rules.”

“I’d just come from work [onTheDays of Our Lives] and had no makeup on,” recalled Rinna. “So I guess I wasn’t playingthathard to get.”

RELATED VIDEO: Harry Hamlin on the Secret to 25 Years of Happiness withLisa Rinna: ‘We’re Diametrically Opposite!’

Besides prioritizing his marriage, Hamlin has been focused on two big projects coming in the next month: his AMC seriesAnne Rice’s Mayfair Witches(premiering Jan. 8) as well as the film80 for Brady(opening Feb. 3).

Along thetwists and turns of his five-decade career, Hamlin tells PEOPLE in this week’s issue that “acceptance” has become one of his biggest life lessons.

“The idea of acceptance and allowing the universe to be what it’s going to be, and accept that it is what it is. Otherwise, you’ll spend your life trying to smash a square peg into a round hole,” he shares. “I spent many years doing that so I decided to toss my hammer away and just accept things.”

For more on Harry Hamlin, pick up the latest issue of PEOPLE, on newsstands Friday, or subscribehere.

source: people.com