Royals Prince Louis Is 'a Cheeky Monkey — a Typical Third Child,' Says Insider Kate Middleton and Prince William's youngest child became an instant star of the Platinum Jubilee celebrations By Stephanie Petit, Stephanie Petit Stephanie Petit is a Royals Writer and Reporter at PEOPLE. People Editorial Guidelines Monique Jessen, and Simon Perry Published on June 8, 2022 01:00 PM Share Tweet Pin Email Kate Middleton and Prince Louis. Photo: Max Mumby/Indigo/Getty Prince Louis showed the world his adorable cheeky side during Queen Elizabeth's Platinum Jubilee celebrations. Kate Middleton and Prince William's youngest child, 4, joined them at Trooping the Colour on Thursday and the Platinum Jubilee Pageant on Sunday, both times bringing laughter to the festivities due to his enthusiastic waves, animated faces and interactions with older siblings Prince George, 8, and Princess Charlotte, 7. "He's a cheeky monkey — a typical third child," someone who knows the family tells PEOPLE in this week's issue. "It's nice that the world got to see him enjoying himself." Kate Middleton and Prince William Crack a Joke About Prince Louis' Cheekiness at the Platinum Jubilee Queen Elizabeth and Prince Louis. Aaron Chown/PA Images via Getty Images Prince Louis even amused his great-grandmother the Queen during Thursday's balcony appearance at Buckingham Palace, with the monarch grinning as the young royal turned to chat with her during the Royal Air Force's flypast — which caused little Louis to cover his ears from the noisy planes at points. To make things even more adorable, Prince Louis wore the same mini sailor suit that his father wore to Trooping at age 2 in 1985. (The same year Louis' uncle, Prince Harry, made his own Trooping the Colour debut!) Even the Duke and Duchess of Cambridge couldn't help but acknowledge their son's scene-stealing behavior. Kate, 40, and Prince William, 39, ended the four days of celebrations on Monday by sharing a social media post that said, "We all had an incredible time, especially Louis…" with the eyes emoji. Prince Louis. Max Mumby/Indigo/Getty On Saturday, Prince Louis stayed home while Prince George and Princess Charlotte accompanied their parents on a visit in Wales. The two eldest Cambridge kids also attended Saturday night's Platinum Party at the Palace, excitedly waving U.K. flags and enjoying performances by Queen + Adam Lambert, Diana Ross and more. Prince Louis had a front-row seat to the festivities again on Sunday, when the Cambridge family gathered for the weekend's big finale: the Platinum Jubilee Pageant. Prince Louis pointed out elements of the parade to Kate, "read" the program and stood up on his seat to get a better look. Although he made a few cheeky faces at his mom, he also cuddled sweetly with Kate — and took turns also sitting on the laps of dad Prince William and grandfather Prince Charles! Kate Middleton and Prince Louis. RICHARD POHLE/POOL/AFP via Getty Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! While the weekend was a celebration of Queen Elizabeth's record-breaking reign spanning 70 years, it was also a look ahead to the future of the monarchy, with Prince Charles, Camilla, Prince William and Kate playing large parts in the events. Adds Sally Bedell Smith, author of Elizabeth the Queen: The Life of a Modern Monarch: "She is in the saddle, but this gets people accustomed to [Charles'] future role asKing. There was a feeling of celebrating the past and anticipating the new era."