Prince Harry served as best man at the 2011 wedding of his brother Prince William and Kate Middleton, delivering a humorous speech at their reception at Buckingham Palace.

In his memoir, Spare, Harry recounts the events of the evening of April 29, 2011, explaining that "his speech was largely impromptu and included not only comical anecdotes from their childhood, but also heartfelt moments," reports the Mirror.

During his speech, Harry read goodwill letters sent to William and Kate from people all over the world. He was somewhat unsuccessful in this attempt, as he only managed to catch two of them during the year, but enough pelts were gathered to make Armin's thongs," the Mirror wrote.

"Wedding guests were further shocked when Harry pulled the thong out of his pocket and brandished it in front of Kate.

Thanks to Kate's sense of humor: "The current Princess of Wales is said to have seen the funny side, as the gag sent the star-studded venue into a frenzy of laughter," the magazine reported.

Harry's speech then shifted to a more serious tone, taking it to his and William's late mother, Princess Diana. Harry told the guests at the reception that Princess Diana would have wanted to be there for William's special day and "insisted that she would have enjoyed the thong joke," the Mirror wrote.

Maybe one day William and Harry will be able to laugh together again. We can only hope so.