"I'm going to marry Patrick," Sir Ian McKellen said slyly during a guest appearance on the U.K.'s Jonathan Ross Show before adding, "I am going to officiate at his wedding."
McKellen broke the news he would be doing the honors when Stewart and jazz singer Sunny Ozell tie the knot after Ross revealed his excitement over the stars reuniting to reprise their roles as Magneto and Professor X in X-Men: Days of Future Past.
When Ross asked how McKellen could legally officiate a wedding, the actor joked saying he didn't know, but he simply planned to "read out the words, and Sunny and Patrick will then be married -- I declare you man and wife."
However, this won't be McKellen's first time officiating. "I've done it once before, with two guys having a civil partnership," McKellen said. "I was crying my eyes out."
McKellen wasn't sure what he planned to wear for Stewart and Ozell's big day, but he joked he was thinking of being more subtle than he had been in the past. "Last time, I went with a sort of gown, white, something I bought in India -- it was rather fetching," McKellen told Ross. "You musn't upstage the bride."
See McKellen's full segment from the Jonathan Ross Show below.