AceShowbiz - James Corden spent most of the royal wedding trying to contain a sneeze as the flowers inside St George's Chapel ignited his allergies.

"The Late Late Show with James Corden" host and his wife Julia Carey flew to England to be guests at Prince Harry's wedding to former actress Meghan Markle - now Meghan, Duchess of Sussex - and while James could appreciate the elaborate floral displays inside Windsor Castle, he admits they played havoc with his nose during the service, and he almost let out a sneeze during an unfortunate moment.

"The worst part of the ceremony for me was there was flowers everywhere, the most beautiful flowers you've ever seen," he said on his chat show on Monday night (May 21). "And I get quite bad allergies if I'm in such close proximity to flowers, so for a lot of the ceremony, I just needed to sneeze."

After demonstrating physically how he looked trying to suppress a sneeze he felt coming, he added, "Right at the point when the Archbishop (of Canterbury) was saying, 'If anyone knows of any reason...' and I was like, 'Please don't sneeze. Please don't sneeze'... I had to do one of those internal sneezes. I think I got away with it."

The 39-year-old, who entertained guests at the evening reception, opened his monologue by gushing about the service, describing it as "one of the most beautiful ceremonies I've ever been to. It was gorgeous, the whole affair, it was happy, it was joyous, it was uplifting."

James, who explained he's been friends with Harry for seven years, then cut to a picture showing him looking grumpy during the service, and added, "In my defence, what face do you make when watching a cellist in a church?"

He concluded by saying, "I was proud to be British on that day. It was a modern, forward-thinking couple having the exact ceremony that they wanted and they brought Britain and the world together for a happy occasion and I was so pleased to be there."