The former teen heartthrob tells PEOPLE that working on the Apple TV+ series was a dream — and Ben Stiller was the best director he’d ever worked with

Actor Robby Benson in 1978 and today. Photo:

Robin Platzer/IMAGES/Getty;Paul Archuleta/Getty

Actor Robby Benson first rose to fame in the ’70s as a super hunky heartthrob who melted hearts in the rom-com Ice Castles. Nearly 50 years later, he found himself cast as the creepy Dr. Mauer, who worked closely with Mark’s wife Gemma in the underbelly of Lumon in the second season of Severance.

So how did the role come to be? Benson tells PEOPLE he just got lucky.

“I got very lucky,” says Benson, 69, who now lives in the Pacific Northwest with Karla DeVito, his actress wife of 43 years.

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“I don’t have a team of people anymore. I’ve been doing this for six decades, and so I figured if someone needs to get in touch with me or wants to find me, they will,” he says. “And I was very lucky that Rachel Tenner, who is the casting director for Severance, had a good idea to hire me. And so I did an audition on tape for Ben [Stiller], and it went well and he was so lovely. I mean, he’s such a good man.”

Benson says that after he landed the part, he couldn’t explain what was happening or what exactly his character was doing, since the show is a constant work in progress.

“By the time I was on set, the script had changed a lot,” he says. “There were all kinds of different iterations and it kept growing and becoming more in-depth, more complicated and very, very cool.”

Robby Benson as Dr. Mauer in season 2 of Severance.

Apple TV+

He will say this about Dr. Mauer:

“He’s a scientist, and he’s probably a sadistic scientist, but the way he was with Gemma, it seems like he was in love with her and he’d never felt anything in his life for anyone else,” he explains. “He’d never experienced love before, and so this was a strange feeling for him. At the same time, he had a job and his job was to put poor Gemma through it.”

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He says the experience was unlike anything he’d ever done before, mainly because of how much attention to detail went into, well, everything.

“From the costume designers to the makeup artists…Ben Stiller knows what he wants and she shoots it until he gets it, and it’s fantastic,” he shares. “These are the most talented and remarkable people in the world that he’s working with, and I fell in love with working with Ben and his crew, people who care so much and just love the job.

When he’s not playing Dr. Mauer, Benson spends most of his time making music with his wife, whom he met when they were in Pirates of Penzance together on Broadway in 1981. Karla had taken over the role from Linda Ronstadt.

“She played Mabel, I played Frederic and Kevin Kline was the Pirate King. I fell in love with her immediately and begged her to marry me for a year. It took a year of begging, and it’s just the greatest thing that’s ever happened to me,” Benson says.

Robby Benson visits Hallmark’s “Home & Family” at Universal Studios Hollywood on May 08, 2019 in Universal City, California.

Paul Archuleta/Getty

“We live with my son and his wife who just had a 𝑏𝑎𝑏𝑦, so there’s a lot of 𝑏𝑎𝑏𝑦 time for me,” he says, adding that he loves being a grandpa for the third time around.

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As for his early fame, back when he was a major teen idol with throngs of screaming fans, he says it was certainly a moment in time.

“By the time I was 12, I was co-starring with Ed Begley Jr. on Broadway in a play called Zelda. But soon after I left to star in the movie Jeremy, which won some awards. I was also writing scripts, and by the time I was 18, I’d sold my fourth script to Warner Brothers.”

(He also famously screen-tested for Luke Skywalker, but lost the part to Mark Hamill.)

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But his role as Nick Peterson in the 1978 rom-com Ice Castles turned him into a major star. “That was a wonderful period of my life,” he says of his 20s. “I loved my fans. But what I remember most about my 20s was meeting Karla and falling in love and having our first 𝑏𝑎𝑏𝑦.”

As for what he thinks of that Severance finale? Benson says what he loved about it most was that it was such a moment.

“I grew up with these pivotal TV memories, like the face in the window of the plane on Twilight Zone. And I think that final scene was one of those television moments that you remember forever. Because you believe in the characters and you’re invested in their love and their lives and what happens to them,” he says. “It’s one of those things you’ll never forget.”

Severance seasons 1-2 are now streaming on Apple TV+.