Kit Harington opens up about fatherhood and how it changed his marriage

"Game of Thrones" alums Kit Harington and Rose Leslie are notoriously private about their lives -- but in a recent interview, the British actor provided a rare glimpse of how their lives have changed since becoming first-time parents.

Harington, 34, opened up to Access Hollywood about being a father and how it brought him even closer to his wife.

When revealing what was the most surprising thing he's learned about being a dad, he confessed, "Everyone goes, 'Look, it's big -- what you're about to go through is big.' You have no way of knowing that until it happens."

"What surprises you is: You go, 'Oh, this goes on forever.' Like, you don't get a break from it," he continued.

Harington said he was surprised by how his marriage evolved in the months since, explaining, "Every day, I wake up and I look after this little human and now we're part of a unit together. I think the thing that surprises me most about fatherhood is you are now a unit, the three of you. And that's a whole new dynamic you need to find."

While not revealing too much about his son, the upcoming "Eternals" star gushed, "I pretty much find every day as he grows and changes and how does that change you. It's a beautiful thing, it really is!"

In the same interview, Harington revealed that Leslie, 34, brought home a puppy last year and he said that taking care of their new pet was "not so different" than taking care of a newborn baby. He also joked that puppies are "great practice" for future parents.

Harington and Leslie, who married in June 2018, welcomed their son in February, but have yet to reveal anything else about him.