As a longtime close friend of Prince William and the so-called "court jester" of the royal set, Pelly, 29, is a natural choice to help organize the celebration. When asked about the party plans by The New York Times, Pelly – who recently opened the London nightclub Public – replied only with a sly grin, followed by a burst of laughter.
But that's just a testament to his friendship with the groom-to-be.
"Guy is very much the life of the party, but he is also fiercely loyal and protective of the princes," royal expert Katie Nicholl told the Times. "There is a lot of history there."
Pelly has been part of the royal entourage – which also includes Prince Harry, 26 – for nearly two decades, getting close to the princes shortly after their mother's death, in 1997. He's such an integral part of the inner circle, in fact, that there's even a character based on him in the upcoming royal wedding movie.
But as much as he's known for his capacity to knock back shots with William and Harry, he's also notorious for his ability to keep rumors under his hat.
As such, while chatter is swirling that the party could be in South Africa, where the trio have raced motorcycles together, Pelly is keeping mum on the details of the bash.
But Nicholl thinks a tightly controlled evening or weekend closer to home is more likely as William enjoys one last hurrah with his mates before he weds Kate Middleton on April 29.
Just don't expect Pelly to share any dish.