David Hyde Pierce Opens Up About His Nearly 40-Year-Long Relationship with Husband Brian Hargrove

David Hyde Pierce knows a little something about love.

In this week's issue of PEOPLE, the Frasier alum and star of HBO Max's Julia reflects on his nearly 40-year-long relationship with husband Brian Hargrove and the secret behind their successful marriage.

"When Brian and I were first together, we were actors, we had the same agents, and we just ran into each other at auditions," says Pierce, 63. "We liked each other. We did not know at that time that either one of us was gay, and we just hung out as best friends. That went on for many months. Eventually, we figured it out."

"I've always felt that the fact that the relationship was built on friendship first is part of the reason why we've been together for 39 years," he adds. "The image I had for a relationship came from my mom and dad, who were together almost 50 years. It was a dedicated relationship. That's what I ended up looking for and ultimately finding."

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Pierce and Hargrove, a 65-year-old TV writer, met in 1982 and married nearly three decades later, on Oct. 24, 2008 — days before the November 2008 passage of Proposition 8, which banned same-sex marriages in California at the time. (Prop 8 was later overturned in court.)

Pierce, who had a successful run of theater, film and television roles throughout his 40-year career, says while he and Brian have been together for so long, he really didn't start publicly talking about his relationship until he found fame on TV.

"At the very beginning of the TV stuff, I was doing an interview with TV Guide and they said, 'Are you dating someone? Are you in a relationship?' I said, 'My life is an open book. Just don't expect me to read it to you.' At the time, I thought it kind of says it all, which is, I'm going to maintain my privacy, but obviously if I say that, you can pretty much guess what the story is," he says.

"At the time, I thought that was enough," he shares. "Now looking back, I think, 'Okay. I tried to not have to make speeches, but I think there are things more important than what I was trying to accomplish.' "

"It was ultimately when I knew I was coming back to the theater, that I started talking very specifically and literally and publicly about Brian," he concludes.

Pierce's new show Julia — a series that will follow the life of the beloved chef and the impact of her long-running television series, The French Chef, which helped pioneer the modern cooking show and popularize French cuisine in America in the 1960s — premieres March 31 on HBO Max.