Amanda Seyfried and Thomas Sadoski are married!

Surprise! Thomas Sadoski let a big bomb slip on Thursday night's Late Late Show, revealing that he and actress Amanda Seyfried had already tied the knot.

When host James Corden tried to congratulate Sadoski on his engagement, the actor called Seyfried "my wife" and held up his shiny new wedding band.

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Revealing they made things official on Sunday, Sadoski added, "We eloped... we just took off into the country with an officiant and just the two of us, and we did our thing... We had a great day. It was perfect.""

The couple wrote their own vows and Seyfried's beloved dog, Finn, was also in attendance.

The newlywed Newsroom alum couldn't stop gushing about his bride, saying, "Listen, she's the person I love, admire, respect most in the world."

He went on to quip to Corden, "I know that you guys are close friends, and I know that she would want you to know, so don't tell anyone."

The couple, who confirmed their engagement in September 2016, are excepting their first child together later this year and couldn't be more thrilled to be first-time parents.

"I'm more excited to be a father with Amanda as my partner than I've ever been about anything in my entire life," Sadoski said on Harry Connick Jr.'s talk show in February. "I couldn't be more proud of her for who she is as a mom already."

Seyfried previously opened up to Vogue Australia about her plans for her future wedding, indicating that she planned to make it a low-key affair.

"I don't want to be the center of attention," she said, adding that she didn't plan to wear a white dress. "I get to go to premieres and get dressed up all the time. I went to the Met Gala last year in a wedding gown designed by Riccardo Tisci; I've played a bride a billion times."

Earlier this month, the couple's Last Word co-star Shirley MacLaine gushed to ET about seeing them in action.

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"Absolutely the best! I watched their love affair, and I watched the baby almost being conceived," she quipped. "To watch the two of them together... they're truly in love."

For more on the couple's romance, watch the clip above!