The Duke of Cambridge has said he is "delighted to be chosen by Prince Harry to be his best man, but joked "revenge is sweet" in an apparent hint at stag party antics.
William’s comments came during a surprise appearance at an event scheduled for just his brother where they highlighted the positive work of a central London sports centre supporting local children.
When the royal siblings first arrived at the Greenhouse Centre in Marylebone, the duke said about being picked to be best man: "Really delighted obviously – revenge is sweet."
Harry’s decision was widely expected as the royal siblings are very close and he was William’s best man during his 2011 wedding to the Duchess of Cambridge.
Harry also shed light on the wedding arrangements, telling the press that the best man announcement on Thursday was not unexpected, stating: “He’s known for months.”
Asked about a name for his new son born on Monday, William smiled and said: “I’m working on that.”
Underneath the public banter, where they regularly poke fun at each other, the pair share a special bond which was strengthened following the death of their mother Diana, Princess of Wales, in a Paris car crash.
William spoke about their connection during 2017 – the 20th anniversary year of Diana’s death – telling Kate during an interview, as Harry, 33, sat with them: “We have been brought closer because of the circumstances as well, that’s the thing.
“You know, we are uniquely bonded because of what we’ve been through.”
Kensington Palace said in a short statement: “The Duke of Cambridge is honoured to have been asked, and is very much looking forward to supporting his brother at St George’s Chapel, Windsor on May 19.”
William and Harry briefly toured the Greenhouse Centre, which is providing a safe place where young people can receive intensive coaching designed to improve their future life outcomes and raise their aspirations.
Housed in a Grade II* listed deconsecrated church, the centre is also accessible to local schools and community members of all ages, and will give teenagers the opportunity to work with high-quality coaches and get active.
The centre, run by the charity Greenhouse Sports, will also be the home for a national table tennis performance club in partnership with Table Tennis England.
Greenhouse Sports was the first delivery partner in London for Coach Core, the national coaching apprenticeship scheme run by Harry’s Royal Foundation.
During their visit, the royal brothers chatted to youngsters taking part in a judo class and tried their hand at table tennis.
On the wedding day, the duke is likely to be tasked with looking after Meghan Markle’s wedding ring and is expected to give the traditional best man’s speech at the private evening event being staged by Prince Charles at Frogmore House.
The Scottish Highlands is one of the top choices with bookies as a stag do destination.
The royals know it well and it will give them the privacy to indulge in outdoor pursuits and keep their antics under wraps.
Rupert Adams, from William Hill, said: “Prince William has been confirmed as the best man, and we think that has increased the chances of a trip to Scotland, which is now 5-2 from 8-1, although Switzerland is the favourite at 6-4.”
Las Vegas – where Harry was photographed partying naked in 2012 – is a 100-1 shot with Ladbrokes as a stag do destination, but a more realistic choice for William is their 5-1 favourite, the Scottish Highlands, or a private hideaway in Wales fancied at 8-1.
London has odds of 20-1, with the royals and their friends possibly partying away at one of the haunts of good friend Guy Pelly.