Prince William had naughty times when he was a kid, too.

A royal fan shared series of photos and videos of the Duke and Duchess of Cambridge with Princess Anne on Instagram to celebrate the latter’s birthday. The ninth slide was a clip showing little Prince William standing on the balcony between his cousins, Peter Philips and Zara Tindall, during Trooping the Colour. They were still kids in the video.

In the adorable clip, Prince William turns to Princess Anne who is standing behind him and he tells her something. When the second-in-line turns to face the crowd he acts as if he is flying an airplane with the gestures of his hand.

Princess Anne leans down and says something to the little prince. It’s hard to tell what the Princess Royal told Prince William, but he suddenly stopped and saluted. Then he continued with his action moves by punching and smashing the air.

The netizens found the clip hilarious especially after Princess Anne’s reaction.

“Happy birthday Princess Anne love that video she was like ‘Good lord William calm down’,” one netizen wrote.

“Kid William was such an energetic bb!!!“ a different user commented.

Another royal fan said that she “laughed so hard over the Trooping the Colour video” with a laughing emoji. According to another royal fan, Prince William was almost 5 years old when the clip was taken in 1987.

“The first is from Trooping The Color 1987 when an almost 5-year-old Prince William was being a little to...much and needed a little reminder to stop! His Aunt stepped in and he stopped but for only a few seconds haha,” the fan wrote.

Another video also featured Prince William and Prince Harry walking down the aisle during the Duke and Duchess of Cambridge’s royal wedding. The netizens noticed how Princess Anne reacted when his nephew pass by them.

“This clip has always been one of my favorite moments of the wedding as you see the groom smiling at his family and them all looking proudly back. But Princess Anne’s smile and face (and her sweet little happy bounce!) is one that always stood out to me: She looked so happy and at the same time so reflective at this young man she watched grow up! It’s quite beautiful,” the royal fan wrote.

Prince William
Prince William attends the unveiling of The Victoria Cross Commemorative Paving Stones representing each of Birmingham's 1st World War recepients at the Hall of Memory, Centenary Square on Dec. 7, 2015 in Birmingham, England. Getty Images/Richard Stonehouse