kate-middleton-looking-prince-william

It looks like Prince William and Kate Middleton are returning from Mustique to attend this special event

The Cambridges have been enjoying a summer holiday in the Caribbean

Ainhoa Barcelona

The Duke and Duchess of Cambridge are enjoying a sun-soaked family holiday in Mustique with their children Prince George, Princess Charlotte and Prince Louis. But the couple are expected to return to the UK some time this week to attend a very special event on Saturday – their friend Charlie van Straubenzee's wedding in Surrey. Twitter has been going wild with suggestions of an upcoming royal sighting, after a royal photographer tweeted that Harry and Meghan will be attending. Harry is thought to be best man.

But further tweets among fans have suggested that William and Kate will also make an appearance. The royal brothers are both good friends of the groom; they attended Ludgrove Prep School in Berkshire as children and have been close ever since. Charlie's brother Thomas van Straubenzee is Princess Charlotte's godfather and was one of William's ushers at his wedding.

The best photos Kate has taken of her children:

Loading the player...

Charlie and fiancée Daisy Jenks' wedding coincidentally falls on Meghan's 37th birthday, so there's no doubt the royals will also be celebrating the Duchess' special day as well as their friend's nuptials. Harry and Meghan are expected to go on holiday later this month, perhaps on a belated birthday trip; last year, the Prince whisked Meghan off to Botswana for an amazing safari adventure.

MORE: Why James Martin has ruled out marriage and babies with long-term girlfriend Louise

William and Kate are expected to attend their friend's wedding this Saturday

Meanwhile, William and Kate have been soaking up the sun in Mustique. The Cambridges joined Kate's parents Carole and Michael Middleton on their annual family holiday. The Caribbean island is the perfect destination for the royals; not only is it ultra-exclusive, it also operates a no-fly zone and other guests are incredibly discreet. William and Kate first visited Mustique in 2008 when they were dating, and have regularly returned.

MORE: Strictly's Brendan Cole opens up about rumoured affair

Scuba diving, snorkelling and playing tennis are just some of the ways the Cambridges can keep themselves occupied. On previous trips to Mustique, the athletic couple have impressed fellow holidaymakers with their diving ability. Martin Katz, a famed Beverly Hills jeweller, and his wife Kelly met the royals in 2008, and speaking exclusively to HELLO! in 2015, Kelly revealed: "They're quite the sportsmen. We went diving and they went very deep, more than 90ft. Our instructor said Martin and I weren't qualified to go on the shark dives they went on."

More on: