Actor and filmmaker Ed Burns believes one simple promise has helped keep his 22-year marriage to supermodel Christy Turlington strong — their “two-week rule.”

The 57-year-old star, who’s been busy working on The Family McMullen — a sequel to his 1995 hit The Brothers McMullen — told Fox News Digital that no matter how busy life gets, he and his wife made a vow early on in their marriage never to go more than two weeks without seeing each other.

“My wife and I, very early on, had an agreement, because our respective jobs do require a bit of travel,” said Burns. “We had a two-week rule where neither one of us was allowed to be gone for more than two weeks at a time. And a lot of times, we had to look at our calendars and sometimes say no to a particular job that would require travel that might have us gone for a longer period of time.”

It wasn’t always easy — both have busy careers and a full family life. Burns and Turlington, who married in 2003, share two children: Grace, 22, and Finn, 19. Now that they’re empty nesters, Burns said they’re a little more flexible, but they still value staying close.

“Now that we’re empty nesters, we don’t have to stick to that in the same way,” he said. “But we still try not to do jobs that will have us away from one another for too long.”

For Burns, who’s spent decades telling stories about love and family, the biggest key to a lasting relationship isn’t complicated. “It’s sort of a cliché answer, I guess, but I think [having] open lines of communication [is key],” he said. “Whether it’s between husband and wife, parents and their kids, or siblings — those are all things we explore in The Family McMullen. And keeping a sense of humor even when things get tough with family.”

That focus on family runs deep in his life and work. Burns said if there’s any similarity between him and his on-screen character Barry McMullen, it’s that “Barry’s a little bit of the butt of the kids’ jokes. That’s probably true in my house.” But he added, “If years from now my kids want to move back home, I’m sure Christy and I would both welcome them with open arms.”

Even with his children grown, Burns said this new season has been “great.” “While we certainly miss the kids, it’s been a very productive time for me,” he said. “I’m getting more writing done now than I’ve ever gotten done.”

Burns also reflected on the man who gave him his big break — Robert Redford. He recalled meeting Redford while working as a production assistant and boldly handing him a VHS tape of his unfinished film. Two months later, he learned his movie had been accepted into the Sundance Film Festival. “Not only did I get to meet Redford after the screening, and thank him for taking the tape and helping us get in, but he was kind enough to let me introduce my mother,” said Burns. “He spent 10 minutes talking to her, telling her what a talented son she had. My mother was over the moon — Redford was her favorite.”

After more than two decades of marriage, Burns’ takeaway is simple and heartfelt: “There is such comfort in family,” he said. “I do think that at the end of the day, it’s a movie that reminds you that having a family that you’re still close to is a real blessing and not to take it for granted.”