Blue split in 2005, but recently reunited to represent Britain at the upcoming Eurovision Song Contest later this month.
The pop stars preceded their imminent performance at the popular singing competition by putting on a show for fans at the U.K. capital's famous G-A-Y Bar on Saturday night.
The show came just a day after Prince William married Kate Middleton, Duchess of Cambridge in London - so Duncan James and his bandmates Lee Ryan, Antony Costa and Simon Webbe, decided to embrace the royal wedding theme by dressing as grooms.
They were backed by a group of hunky dancers in bridal dresses, and during the concert the pop stars thrilled the crowd by tearing off the gowns and stripping the men down to skimpy underpants.
James said after the show, "The whole nation is feeling so patriotic this weekend, that we really wanted to do something as a tribute to William and Kate."
"As we're representing the U.K. ourselves in just under two weeks, how could we not get behind the royal wedding fever? The feeling of support for the U.K. currently is amazing. When we've travelled round Europe promoting Eurovision there is a really good feeling for us Brits out there. Hopefully the royal wedding fever is gonna help us get (full points) at Eurovision."