Bradley Whitford Was ‘Surprised’ by How ‘Comfortable’ He Was Playing Allison Janney’s Husband on ‘The Diplomat’ (Exclusive)

Bradley Whitford and Allison Janney’s onscreen reunion was a long-awaited one, and it surprised the actors in an unexpected way.

Whitford joined season 3 of The Diplomat as Todd Penn, the better half of Janney’s Grace Penn, who finds herself unexpectedly at the helm of the White House when the season begins.

Working on the show — which centers on Keri Russell’s Ambassador Kate Wyler and her complicated relationship with her husband and fellow foreign service officer Hal (Rufus Sewell) — “exceeded my wildest expectations,” Whitford tells PEOPLE.

“I would do yard work for Julia Moore Debora [Cahn] or Allison. It was a show that I loved. And it was just a really joyous experience,” he quips.

More seriously, though, Whitford, 66, says that what “surprised” him about the show was how seamlessly he and Janney — who have been like “family” ever since starring on The West Wing together — played into the romance.

“If there was one thing that surprised me, it was the ease of taking the history we have together and shooting it down a different road,” he says. “It felt very comfortable. There was no… We’ve actually done other little things together, but it was particularly fun to bring that history into a marriage.”

Janney, 65, agrees. “It was so easy and comfortable,” she tells PEOPLE. “Having to do totally different characters [than The West Wing] — characters who go to bed together — and that was an interesting scene when I read that, and it ended up being one of my favorites.

“It was really fun and easy and comfortable with Brad because of our history together. I think it would’ve been more difficult with someone I didn’t know. It was surprisingly really easy and really fun.”

She adds, “I was just excited for everyone on Diplomat to get to meet Brad and experience everything that is Brad, which is fabulous and joyful and just — he’s the dream.”

Cahn previously told Netflix’s Tudum that Whitford “was the fantasy version of Todd” for everyone behind the camera as they got season 3 together.

“We still can’t believe it came true,” she said, while executive producer Janice Williams called the actor “the perfect addition to what is already a dream cast.”

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The Diplomat season 3 is now streaming on Netflix.