The 33-year-old father of two was caught getting a reprimand from Queen Elizabeth II in London during last week's Trooping the Color parade in a 5-second clip that's since blown up on social media.
The equally endearing and hilarious gesture shows the queen swatting William with the back of her hand on the Buckingham Palace's balcony, apparently for not standing as he tends to his 2-year-old son, George.
"Stand up, William," the GIF's added commentary suggests her saying.
Adding to the comedy of the clip, little Prince George appears to deliver a facepalm in response to the rebuke as William's younger brother, Prince Harry, quickly erases his own smile and stands at attention behind them.
The clip has since gone viral on the web and it's been retweeted more than 6,000 times as of Sunday.
Other clips show that Prince George was just trying to shield himself from the sun -- not from his father's embarrassing blunder.
Pittsburgh news editor Brandon McGinley, who shared the clip on his Twitter page Wednesday, expressed a bittersweet response to his tweet's overnight fame.
CORRECTION: A previous version of this story stated incorrectly that Prince William is third in line to the British throne. He is second in line to the throne.