Dawber was signed for a four-episode arc, so in honor of the occasion, Parade.com is taking a look at how Harmon and Dawber’s relationship began, why it’s successful, when they had kids and more.

How did Mark Harmon and Pam Dawber meet?

Dawber met Harmon at a party thrown by a mutual friend, and even when they were first dating, they managed to keep their relationship private even though they were both well-known celebrities. Dawber says it was more about self-preservation than anything else. “We’re not trying to keep something secret, but if you don’t want it totally exploited by the press, you have to,” Dawber told PEOPLE.

When did Mark Harmon and Pam Dawber get married?

Harmon and Dawber tied the knot March 21, 1987 in the chapel at the Harvard-Westlake School in Studio City, Calif., according to the Associated Press. Harmon was an alum, having graduated from the school in 1969. In attendance were a small group of friends and family. The following day, at a barbecue at their home, the couple made the announcement to a larger group before heading off on their honeymoon to Vancouver, British Columbia, where Harmon was filming the movie After the Promise.

What’s the secret to their successful marriage?

“There’s no quick answer, no key. I just feel fortunate,” Harmon told Parade. “She’s a neat lady.” Harmon also told PEOPLE, “We were both in our 30s when we got married, so hopefully the stupid stuff, we did earlier. That’s probably the closest I have to what the key is.”

Do Mark Harmon and Pam Dawber have kids?

They have two boys: Sean Thomas Harmon, born April 25, 1988, and Ty Christian Harmon, born June 25, 1992. Sean is also an actor and has played Special Agent Leroy Jethro Gibbs several times on NCIS when the script called for a younger version of the character.

Why did Pam Dawber quit acting?

While Dawber had found success with Mork & Mindy and My Sister Sam, when she became a mother, her priorities changed. She decided she wanted to be home to raise her kids, instead of hiring someone to help. “I had children and it was like, ‘I’m not going to chase this fame thing,’” Dawber told Closer Weekly. “I wanted to drive my kids to school. I wanted to be there for their birthdays and bring cupcakes and doughnuts. And I was very happy to do it.” And while Harmon didn’t give up his career, he and Dawber chose to keep their kids out of the spotlight. “It’s not even a choice,” Harmon says of his lowkey lifestyle in that same story. “It’s who we are. We stay home. A lot. I’m not a Twitter guy or a Facebook guy. Our sons aren’t into that either. Pam and I have both made a living in this business, and still, there’s a part of that that’s just not natural.”

Has Pam Dawber been on NCIS before?

No, tonight is her debut performance. “I’ve been asked to do NCIS before over the years. It just wasn’t the right character or the right time,” Dawber told TV Insider. “With Marcie, it was so funny because when they were casting, Mark goes, ‘Who you’re really looking for is my wife.’ They said, ‘But she’s always turned us down!’ I read the script and I’m going, ‘Oh no.’ My fear rockets flew off.” She admitted she was afraid to film NCIS because it had been so long since she last acted. “I finally thought I’d feel worse if I chickened out.” She revealed Harmon didn’t jump at the opportunity to rehearse at home.“I’d say, ‘Let’s run lines,’ and Mark would be like, ‘OK, but can we watch this game?’” She continued, “But it was all really effortless. I felt so safe on that set. I know everybody. Rocky Carroll directed, and I love working with directors that have been actors—they really know.” Of whether Marcie and Gibbs get along, she revealed, “This is the first time a character is not scared of Gibbs.” She continued, “She’s a strong woman. They’re trying to figure each other out, but they’re opposite ends of the spectrum as far as their personalities. He frustrates the hell out of her with his mumbling Gibbs’ one-liners. She’s a chatterbox. There’s a lot of humor—character humor, not joking humor. We play against each other. That comes naturally. It’s fun. We’ve had a blast.”

Have Pam Dawber and Mark Harmon worked together on a movie or TV show before?

Harmon and Dawber have only acted together on screen one time, in a movie called I’ll Remember April. But they have done theater productions of Love Letters. Harmon told The AV Club, “Onstage, we’ve done a number of different productions of Love Letters in different places. I was a Bob Clark fan—actually, my wife is, too—and it’s just a good script. A good story. But the plan was not to work opposite my wife from the beginning. She’s got her own brain and her own decision process. But it was interesting for all those reasons. Fun to do. And different.” Watch the two when Dawber makes her debut on NCIS tonight at 8 p.m. ET/PT on CBS. Next, find out if Mark Harmon will be leaving NCIS anytime soon. 

Who Is Mark Harmon s Wife Pam Dawber  - 45Who Is Mark Harmon s Wife Pam Dawber  - 99