Pam Dawber and Mark Harmon.Photo: David Livingston/Getty

When it came to asking out his wifePam Dawberfor the first time,Mark Harmondid not beat around the bush.
The formerNCISstar tells PEOPLE a cold call led to their first date — 37 years ago.
A mutual friend wanted to set him up with theMork & Mindystar via a group date, Harmon recalled to PEOPLEas he discussedhis new historical non-fiction book,Ghosts of Honolulu: A Japanese Spy, a Japanese American Spy Hunter, and the Untold Story of Pearl Harbor, out Nov. 14.
But Harmon, 72, preferred a more direct approach. “I said, ‘Can I just call? Can I get a number and just cold call?’ And so I did. I got the number, and I called, and I got an answering machine. And I started to leave a message that said, ‘We don’t have to all go out. We could get a cup of coffee or something.’ And then she was monitoring and she picked up. We went out that night and we’re together ever since.”
The two married a year later “to the day,” he says.
Mark Harmon and Pam Dawber in 2002.Ron Galella/WireImage

Ron Galella/WireImage
That fateful first date came shortly after Harmon was crownedPEOPLE’s Sexiest Man Alivein 1986. In that cover story interview, Harmon told PEOPLE that while he wasn’tlooking for a relationship, he was holding out for a marriage that would last.
Today the couple share two children in their thirties, sons Sean, an actor (who has appeared onNCIS), and Ty, a screenwriter. “I’m proud of our boys,” says Harmon. “They understand the work ethic and they’re very different.”
What’s the secret to his and Dawber’s longevity?
“I have no secret,” says Harmon. “We laugh. You got to laugh, and you got to talk and communicate. That’s the fun part. Do we sit and talk about it? No. Maybe you just get fortunate and find the right one. We share many things and yet we’re really different.”
Mark Harmon and Pam Dawber in 2013.Kevin Mazur/WireImage

Family time was a big factor in his original decision to play Special Agent Gibbs onNCIS,which ultimately became a 19-season runwith Harmon in the leading role.
“It was importantto be able to make pancakes on Saturday morning,” says Harmon, who would go on to share scenes with Dawber onNCISduring her story arc as journalist Marcie Warren.
“And there were some times where that meant not sleeping. You just came home and took a shower and came back down. And yet I look back at it and I don’t miss the sleep. I still missed things, I was working, but I’ve been part of [my sons’] lives. I’ve been able to spend more time with them. In many ways, we’ve had a great opportunity to kind of grow as a family.”
Gratitude, says Harmon, remains a constant in his life. “I’m so fortunate," he says. “I don’t ever wake up not thinking that.”

Never miss a story — sign up forPEOPLE’s free daily newsletterto stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
source: people.com