The Star Trek and X-Men actor explains that the two never got close until they worked together on 2000's X-Men, in which Stewart plays Professor Charles Xavier, aka Professor X, and McKellen plays Erik Lehnsherr, aka Magneto.

"We had adjoining trailers," Stewart began. "On those kind of movies, you spend more time sitting in your trailer than you do in front of the camera. So, Ian and I hung out together, drinking tea — and maybe in the afternoon, something a little stronger — and we got to know one another."

He continued, "And the charm of it was that we found that we had so much in common. And by the way, he married us, my wife and me. He performed the ceremony." (Stewart married singer Sunny Ozell in 2013.)

Another unique aspect of Stewart and McKellen's friendship is that they have both been knighted, an experience Stewart also talked a bit about for Wired.

Stewart joked he didn't know how he managed to be bestowed the title, but "that evening, I did call my wife, and I said to her, 'Oh, hello. Is Lady Stewart home?' because my wife has got a title also now."

Stewart and McKellen met decades before X-Men when they'd done a production of Tom Stoppard's Every Good Boy Deserves Favour at the Royal Shakespeare Company, but weren't close at the time and didn't keep in touch in the intervening years.

Stewart is currently starring in Picard on CBS All Access.

Watch his full segment below.