Cameron Diaz has only one way to describe her marriage Benji Madden. “It was the best thing that ever happened to me,” she told her brother-in-law Joel Madden — her husband’s twin — during the Dec. 10 episode of his “Artist Friendly” podcast. And the Bad teacher The 52-year-old star opened up about what keeps their nearly decade-long union running smoothly.

“Therapy is a big thing in our family, thank God,” Cam said. “It’s what we depend on, so have the commitment to work on it.” Joel, 45, quickly added that he and his wife Nicole Richie43, are also dedicated to advice. “It’s like going to the gym and learning new moves and building strength,” shared the host, who previously opened up to his spouse about not pretending to be “perfect”: “We’re going to Therapy – lots of therapy.”

In fact, both couples might not be where they are today without the help of professionals. “Cameron and Nicole agree that counseling has saved each of their marriages,” a source exclusively reports Life & Style. “That’s what they rely on to keep their individual relationships healthy.”

Cameron Diaz considers Nicole Richie a “role model”

Although Nicole may be younger, she and Joel have been together since 2006 and married since 2010, so Cameron looks to her as a role model when it comes to keeping a romance in the spotlight. “She looks up to Nicole, who basically led her in the direction of therapy,” the insider claims, noting that Cam has been known to date men like him Matt Dillon60, Jared Leto53, Justin Timberlake43, and Alex Rodríguez49, before tying the knot with Benji, 45, in January 2015. “They practice open communication, honesty, taking time for themselves, date nights without the kids, and the simple rule of not going to bed angry. The relationship tools each of them have acquired are invaluable.”

Cameron points out that counseling is particularly helpful when it comes to changing destructive patterns so that she and Benji can avoid “doing the same thing over and over again.”

“Let’s be confident,” said the actress, “and let’s be a little more prepared the next time we try it, hopefully coming out with a different result.”

Of course, couples therapy only works if both parties are willing to put in the necessary effort. “It’s about wanting to do it,” Cameron shared. “You can’t get married and start a family if … both people aren’t 100 percent every day. No one can be 99 and the other 100.”

Luckily, Good Charlotte’s bandmates are up for the challenge. “You have to give Benji and Joel the same credit because these are guys who may look tough but are in touch with their feelings,” says the insider. “You know a happy wife means a happy life.”