Via ShowTracker, a Los Angeles Times TV blog:

On Thursday night O'Brien's longtime costume designer Scott Cronick married his partner David Gorshein. While Gorshein waited underneath the chuppah, Cronick walked down the aisle accompanied by his favorite celebrity, Andy Cohen of Bravo.

Onstage, the couple exchanged heartfelt vows. "Anyone in the world would be happy to wear one of your designs, but no one is possibly happier than I am to wear your ring," Gorshein said.

... After the men stepped on two glasses (one for each groom), O'Brien declared, "By the power invested in me by the state of New York and the Universal Life Church, I now pronounce you husband and husband. You can kiss the groom."

[You can watch the segment here.]