Sir Ian McKellen is to officiate at his X-Men co-star Patrick Stewart's upcoming wedding.

The gay star, who played Magneto opposite Stewart's Professor X in the comic book movie adaptation, has revealed he can legally wed friends and will step up when his thespian pal weds jazz singer Sunny Ozell in the U.S. later this year (13).

MCKellen tells U.K. Tv chat show host Jonathan Ross, "In Massachusetts, in the middle of America somewhere, you get a friend along, and I read out the words, and Sunny and Patrick will then be married... I’ve done it once before with two guys having a civil partnership. I was crying my eyes out."

Massachusetts' Secretary of Commonwealth offers a service that allows a family friend or relative to perform a couple's wedding ceremony.

MCKellen and Stewart will reprise their X-Men roles in flashback scenes in the upcoming prequel, X-Men: Days of Future Past.