The REAL reason Princess Charlotte stuck her tongue out at Kate and William's sailing regatta

What a moment!

Princess Charlotte and her brother Prince George thrilled royal fans when they made a surprise appearance at the King's Cup royal sailing regatta alongside their parents and grandparents on Thursday - and cheeky Charlotte certainly amused the crowds when she decided to stick her tongue out at them with her mum the Duchess of Cambridge! The moment came when 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, playful Princess Charlotte instead decided to pull the funny face - while Kate can't stop giggling. 

It's since been revealed that Charlotte stuck her tongue out because she'd spotted her granddad Michael Middleton down below! The Duchess had in fact wanted to show her children a familiar face in the crowd before they took their places in front of the stage for the prize-giving, and so she pointed her father Michael out for Charlotte to see. The four year-old's response certainly gives a sweet insight into their playful relationship! 

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

Fans were thrilled to see Charlotte and George

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.

The kids enjoyed a day out watching the races

The royals and celebrities involved in the regatta were each representing a charity that the royal couple support. The Duke sailed for Child Bereavement UK while the Duchess skippered a boat for the Royal Foundation. Other charity teams included 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 - hilariously bagging herself a giant wooden spoon! 

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