The four-year-old could be seen pointing, chatting, and even sticking his tongue out at his mum, the Duchess of Cambridge!
Both his parents were in good spirits throughout the event, which took place on Sunday afternoon, but Prince William clearly laid some ground rules for his youngest son.
In a video of the royal box, the young boy can be seen climbing down from his mum's lap and going to ask William a question. The dad-of-three shakes his head before chatting to his son for a while, after which Louis heads back to his seat.
WATCH: Prince William denies Prince Louis' request in unseen video
It appears from William pointing behind him and Louis looking in another direction that the youngster wanted to move around the venue, but he was only allowed to sit with his parents or Prince Charles and the Duchess of Cornwall.
Louis was later seen sitting on his dad's lap, and also spent some time cuddled with his doting grandfather, who helped to keep the youngster entertained.
Louis sat on Prince Charles' knee for a while
The royals were out in force to enjoy the final day of the Jubilee celebrations. As well as Prince Louis, Kate and William's older children Prince George and Princess Charlotte attended the pageant, as did Zara and Mike Tindall and their children, and Zara's brother Peter and his children.
Princess Eugenie and her husband Jack Brooksbank were also spotted – as was their baby son August, who appeared to be intrigued by the performers on display!
Louis cuddling his mum in a quiet moment
Princess Beatrice attended alongside her husband Edoardo Mopelli Mozzi and his six-year-old son Woolfie, and of course, Prince Charles and Camilla.
Louis attracted a lot of attention from royal watchers thanks to his dancing and animated facial expressions, and his devoted parents even made reference to his behaviour in a social media post after the event, writing: "We all had an incredible time, especially Louis… [eyes emoji]. W & C."
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