The Duke of Cambridge and a newly single Prince Harry will watch one of their closest friends, Guy Pelly, wed in the US at the weekend.
The royal brothers are heading to America to be guests as London nightclub owner Mr Pelly marries hotel heiress Elizabeth "Lizzy" Wilson at the Memphis Hunt and Polo Club near Elvis Presley's Graceland mansion in Tennessee on Saturday.
Palace aides will be hoping for a low-profile trip for Harry, who split from girlfriend Cressida Bonas this week, and William, who has just returned from a successful overseas tour to New Zealand and Australia and is expected to travel without wife the Duchess of Cambridge and baby son Prince George.
A jaunt to the US by Harry in 2012 hit the headlines when he cavorted naked with a girl during a game of strip billiards in a Las Vegas hotel.
Mr Pelly, a close friend of the pair for many years, was often cited as a bad influence on the brothers in their youth. The son of wealthy Kent landowners, the 32-year-old, who helped organise the Duke's stag do, was dubbed William and Harry's "court jester" for his wild ways.
He dressed up as the Queen and imitated her voice in 2005 when Harry was infamously photographed wearing a Nazi uniform at a fancy-dress party.
The former Stowe public schoolboy met William and Harry through the Beaufort Hunt.
His three-day wedding party is due to kick off tomorrow with drinks, followed by the wedding and a fancy dress reception on Saturday and a brunch on Sunday.
Cressida, who split amicably from 29-year-old Harry as they called time on their two-year relationship, is rumoured to not now be attending the wedding.
William separated from Kate temporarily in 2007, four years before they married, prompting speculation that Harry and Cressida might eventually get back together.