Prince Louis was an adorable star of the show on the Buckingham Palace balcony, pulling faces and covering his ears next to the Queen during the Jubilee fly past.
The Duke and Duchess of Cambridge's youngest son, four, joined his family to appear on the famous balcony to watch a fly past in the spring sunshine on Thursday lunchtime.
He appeared alongside his brother Prince George, eight, sister Princess Charlotte, seven, and parents the Duke and Duchess of Cambridge for the event.
During the flypast, the prince was spotted interacting with his great-grandmother, before covering his ears as the aircraft soared overheard.
He earlier took a seat in the first carriage for the Queen's Platinum Jubilee birthday parade along The Mall in London.
Her Majesty took the time to bend down and speak with the little Prince, who looked up at the 96-year-old to listen to her every word.
In the morning, Prince Louis had leaned out the window of Horse Guards and did a small salute at the Irish Guards as they continued to parade for the Trooping the Colour.
George looked the image of his father in a smart navy blazer and pale blue tie, which fitted perfectly into the colour pallette of the carriage.
Charlotte took on her role at the back of the carriage with aplomb, grinning and waving at the crowd as she went down The Mall in her pale blue dress.
It featured a sweet but subtle bow at the collar but was largely simple in structure, showing her growing into her role as a young public-facing royal.
Read more: 17 times Princess Charlotte stole the show
Louis wore a sailor-style outfit that once belonged to Prince William, often reserved for the royal children and based on the style worn by the Royal Navy.
The white top features a large collar with a striped navy edging, and a neckerchief beneath the collar.