“How did I ask?” Harry told reporters during a visit to the Greenhouse Center charity in London. “Got down on one knee. He’s known for months.”
Kensington Palace announced on Thursday that William (who just welcomed his third child with Kate Middleton on Monday) would serve as Harry’s best man at his May 19 wedding to fiancée Meghan Markle, just as Harry did for William back when he married Kate in 2011.
“It feels great,” William said of the honor of standing by his brother’s side on his wedding day. “Thrilled and delighted, obviously.”
William couldn’t resist slipping in a joke of his own — and perhaps a warning to Harry ahead of a potential wedding toast: “Revenge is sweet.”
RELATED VIDEO: Prince William Shares Sweet Moment with Meghan — and Drops Hint About ‘Strong’ Baby Name!
The brothers (who were matching in white shirts, black pants and blue jackets) teamed up to officially open the Greenhouse Center, a London-based organization that will provide sports and social opportunities, as well as coaching, to young people in the community.
- Can’t get enough of PEOPLE’s Royals coverage? Sign up for our newsletter to get the latest updates on Kate Middleton, Meghan Markle and more!
Of course, William was also asked about the yet-to-be-revealed name for his baby boy. Yesterday, William said the name was a “strong” one, but today, implied that he and Kate may still be doing some thinking. (Or just waiting until they have a chance to introduce the newest member of the family to his grandparents and great-grandparents.)
“I’m working on that,” he said, before reassuring the crowds. “You’ll know soon, you’ll know soon.”