The love birds, who are expecting their first child, married in a secret ceremony over the weekend — and fans were none the wiser.
“We eloped. We just took off into the country with an officiant and, just the two of us, and we did our thing,” Sadoski, 40, revealed during a Thursday appearance on The Late Late Show with James Corden.
Sadoski showed off his own wedding band on the talk show, proudly holding up his left hand as he declared Seyfried his wife.
“Listen, she’s the person that I love, admire, respect most in the world,” Sadoski continued, noting that he and Seyfried, 31, wrote their own vows.
“It was beautiful. It was everything that it should be,” he said. “It was just the two of us talking to each other.”
He also opened up about becoming a father, telling, Corden: “I’m more excited about this than I’ve ever been about anything in my life. And I’m also more terrified about it than anything I’ve ever been in my entire [life.]”
Seyfried has not spoken publicly about the secret wedding, but alluded to the news in an Instagram post on Thursday.
“This nice man is going to be on @latelateshow tonight to talk about nice things!” she wrote alongside a photo of Sadoski.
Seyfried and Sadoski first met while working together on the off-Broadway show The Way We Get By in 2015, and began their romance when they reunited on the set of their upcoming film The Last Word. PEOPLE confirmed their relationship in March 2016.