Royals See Kate Middleton Jump Into Mom Mode After Princess Charlotte Playfully Sticks Out Her Tongue! Kate Middleton and Prince William faced off in a charity sailing race on Thursday, with their two eldest children watching the action from a boat By Stephanie Petit Stephanie Petit Stephanie Petit is a Royals Writer and Reporter at PEOPLE. People Editorial Guidelines Published on August 8, 2019 01:25 PM Share Tweet Pin Email Trending Videos Princess Charlotte is stealing the show once again! Kate Middleton and Prince William faced off in a charity sailing race on Thursday, with their two eldest children watching the action from a boat (and Prince George looking adorable in a captain’s hat!) alongside their grandparents, Mike and Carole Middleton. But when Kate brought the kids to a window above the stage where prizes were to be awarded, Charlotte showed off her cheeky side. Instead of waving to the crowd, the 4-year-old princess decided to stick out her tongue — which mom Kate quickly tried to stop her from doing. Meanwhile, Prince George didn’t seem to be fazed by the commotion and headed downstairs. Princess Charlotte and Kate Middleton. ADRIAN DENNIS/AFP/Getty Princess Charlotte and Kate Middleton on charity sailing day 2019. ADRIAN DENNIS/AFP/Getty ADRIAN DENNIS/AFP/Getty See the Best Photos of Prince George, Princess Charlotte, Kate Middleton and Prince William at Sea! Aaron Chown/PA Images via Getty This isn’t the first time that Princess Charlotte has showed off her tongue-waging. At uncle Prince Harry‘s May 2018 wedding to Meghan Markle, the royal pulled the move as her car arrived at St. George’s Chapel in Windsor Castle. (Of course, her royal uncle would probably approve — as a youngster himself, Harry made a silly face out the car window after a visit to the hospital when his cousin, Princess Beatrice, was born in 1988. Andrew Milligan - WPA/Getty Images; Daily Mirror/Mirrorpix/Getty Images Kate is always ready at a moment’s notice when it comes to keeping her children on their best royal behavior. After five jam-packed days of their royal tour in Poland and Germany in 2017, Princess Charlotte got a little fussy before heading back to London on a private plane. But mom Kate put her expert squat and chat skills to the test, immediately calming her royal toddler down and putting a smile on her face. William then helped her onto the plane. Chris Jackson/Getty Chris Jackson/Getty Kate also swooped in to comfort Princess Charlotte after the little royal took a spill on the Buckingham Palace balcony during the 2018 Trooping the Colour flypast. After looking in her Royal Air Force booklet and excitedly peeking over the balcony in anticipation of the next plane to pass by, Charlotte lost her balance and started to fall backward. She reached for stability, but luckily Kate was there to steady the little princess. Kate bent down to chat with a visibly-shaken Charlotte, and then picked up her daughter, quickly defusing the moment. Charlotte went on to enjoy the rest of the flypast, excitedly clapping and following along while standing next to Queen Elizabeth’s great-granddaughter Savannah Phillips. James Whatling/MEGA Frank Augstein/AP/Shutterstock The King’s Cup Regatta was originally scheduled for Friday, but due to forecasted bad weather in Cowes on the Isle of Wight, the race was moved up a day. Kate and William each acted as skippers of competing vessels — state-of-the-art Fast-40 boats — for the chance to win the King’s Cup, a historic trophy first presented by King George V at Cowes’ Royal Yacht Squadron in 1920. Kate Middleton. Chris Jackson/Getty Kate Middleton and Prince William. Trevor Adams/Matrix/MediaPunch Eight boats took part in the race, each representing a charity being supported by the royals. This year, Kate’s four charities that were represented are Action on Addiction, Place2Be, the Anna Freud National Centre for Children and Families, and The Royal Foundation. Child Bereavement UK, Centrepoint, the London Air Ambulance Charity 30th Anniversary Campaign, and Tusk, four causes for which William is a patron, also competed. Tusk Trust, with Bear Grylls at the helm, won the first race, with Prince William coming in third and Kate placing seventh. Prince George. Karwai Tang/WireImage Princess Charlotte (left). SplashNews.com Can’t get enough of PEOPLE’s Royals coverage? Sign up for our newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! Both George and Charlotte were dressed appropriately for the nautical occasion, rocking blue and white stripes (Charlotte’s sleeveless dress is by Ralph Lauren Kids). Of course, they covered up their outfits with lifejackets while on the boat. While Kate and William, both 37, were busy competing, they remained under the watchful eye of Kate’s parents. Prince Louis, 1, was also on the Isle of Wight for the event, likely in the care of the family’s trusted nanny, Maria Teresa Turrion Borrallo.