“Game of Thrones” stars Kit Harington and Rose Leslie, who have dodged relationship rumors for more than three years, have finally stepped out as a couple.

Harington first made the revelation on Britain’s “The Jonathan Ross Show” Saturday, telling the host, “I fell in love in Iceland,” where some of “Game of Thrones” is filmed. “I fell in love with my co-star,” he explained. As the screen showed a photo of Harington and Leslie, both 29, in their respective roles as Jon Snow and the newly deceased Ygritte, Ross joked, “This is Rose . . . who is just the loveliest girl and she could do so much better!”

The following night, Leslie and Harington made their red-carpet debut as a couple at London theater’s 40th Olivier Awards, held at the Royal Opera House. Native Londoner Harington wore a tuxedo while the Aberdeen, Scotland-born Leslie sported a Malene Oddershede Bach gold gown, People magazine said Monday, reporting that the two shared a quick kiss on the carpet.

Rumors of a relationship had arisen in 2012, the magazine said, adding that while any romance apparently died out later that year, it eventually rekindled. Then this January, photos appeared of Harington and Leslie behaving romantically during a Los Angeles shopping trip, prompting fellow “Game of Thrones” star Emilia Clarke to tell “Entertainment Tonight,” “Well, you know, we like to spread the love on our show. It’s a beautiful thing. She’s one of my best friends, so it’s good. . . . I mean, there’s worse things than be caught kissing Jon Snow!”

On March 28, additional romantic images of Leslie and Harington emerged on Twitter, showing them kissing in what appears to be a diner.