Holly Schumacher

While O'Brien never actually RSVP'd, he showed up nonetheless.

"I was standing in Park 75 [the restaurant in the Four Seasons] and looked up and saw this towering man with big, red hair and a black leather jack walk in," Wes, the groom, recalled. "He just gracefully walked in, and I walked over and met him and introduced myself. We joked around for a bit, and he showed me how to do his string dance that he does."

After chatting with the bride and groom, O'Brien went over to the bar and ordered a whiskey cocktail, and talked with guests and took pictures with them. Several of the ladies in the wedding party tried their best to get him to take a lemon drop shot, but he politely refused.