Video: Watch Princess Charlotte stick her tongue out at sailing regatta

This is hilarious!

Princess Charlotte was in a playful mood as she enjoyed a day out at the King’s Cup sailing regatta in Cowes on Thursday! The four-year-old joined her big brother Prince George for a fun family day at the event, which her parents Prince William and Kate were competing in, and couldn’t resist playing up to the crowd who were excited to catch a glimpse of the royals.

Kate encouraged her two eldest children to wave to the crowd through a window, but while George can be seen walking away down a flight of stairs, cheeky Princess Charlotte stuck her tongue out – much to the amusement of her mum and the people who were gathered outside.

Watch Princess Charlotte poke her tongue out at the crowd at the King's Cup Regatta

George and Charlotte were treated to a fun outing with Carole and Michael Middleton as Prince William and Kate competed in the regatta. The royal children were pictured in a boat with their grandparents earlier in the afternoon, with George, six, looking the part in a captain's hat, while Charlotte was spotted inside the vessel.

GALLERY: See all the best photos from Prince William and Kate's day at the King's Cup Regatta

The Cambridge children had earlier enjoyed a fun morning on the foreshore in Cowes, taking part in family activities including a tug-of-war with other youngsters. They also enjoyed bubbles, an entertainer dressed as a pirate and a magician ahead of the afternoon's racing. Prince Louis, one, did not join his siblings for the outing, but was also on the Isle of Wight for the event.

Kate had encouraged her daughter to wave to the crowd

During the engagement, William and Kate took to the water to each skipper a boat, competing against one another and six other celebrity ambassadors: comedian John Bishop, adventurer Bear Grylls, England Women's footballer Fara Williams, television presenter Dan Snow, BBC presenter Katie Thistleton and Olympic champion rower Helen Glover.

STORY: Prince George and Princess Charlotte look adorable in nautical stripes

The royals and the celebrities were each representing a charity that William and Kate support. The Duke sailed for Child Bereavement UK while the Duchess skippered a boat for the Royal Foundation. Their other charities that they supported were Centrepoint, London's Air Ambulance Charity's 30th anniversary campaign, Tusk, Action on Addiction, Place2Be and the Anna Freud National Centre for Children and Families. Bear Grylls' team won the first race, while William's team came third and Kate's group placed seventh out of eight.

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