As the royal family took to the balcony of Buckingham Palace for the RAF flypast during today’s Trooping the Colour, Kate had a simple but firm instruction for her youngest son, according to a lip reader

As the royal family made their highly-anticipated appearance on the Buckingham Palace balcony during today’s Trooping the Colour, Princess Kate seemingly had a simple but firm command for Prince Louis. The young royal was on his best behaviour during the King’s birthday celebrations, despite many hoping that his signature cheeky antics would once again be on display.

Although Louis was mostly kept in check by his siblings George and Charlotte, Princess Kate did have to issue one simple instruction, according to lip reader Jeremy Freeman. As the royals took their pride of place before they headed back inside Buckingham Palace after the Red Arrows flypast, the lip reader claims that Kate had to instruct Louis to call to attention for the national anthem.

Kate had a stern two-word instruction for a fidgety Louis on the Palace balcony(Image: Ian Vogler / Daily Mirror)

Freeman exclusively told The Mirror that the young royal was looking restless as the festivities drew to a close, prompting Kate to say to her children: “National anthem. Louis, stand.” Louis then straightened his posture and focused for the signing of the national anthem.

Elsewhere on the balcony, King Charles and Prince William apprently remarked on what a spectacular day it had been, praising the military parade and the Red Arrows stunning aerial show.

According to Freeman, William turned to his father at the conclusion of the RAF flypast and said: “Oh my word, what a day,” to which Charles replied: “Great theatre.”

Kate told Louis to “stand up” for the national anthem, while Charles and William discussed the wonderful day(Image: Ian Vogler / Daily Mirror)

During another wholesome moment on the balcony, the three generations had a candid chat about the aircraft featured during the flypast.

Freeman said that while William was having a conversation with Kate, King Charles interrupted to say: “What is that?” as he pointed to an aircraft flying over the balcony.

William responded to his father, further asking: “Errr is that Poseidon?” Prince George then stepped in to the conversation, confirming: “It’s a Poseidon, yeah.”

Prince George took over a conversation with his father and grandfather about the RAF flypast(Image: PA)

It comes as upon the conclusion of the King’s birthday festivities, the royal family shared a series of videos showcasing the highlights of the day. In a short video posted by William and Kate, William is seen leaving the Palace in his military garb and mounting his horse for the procession, while Kate, George, Charlotte and Louis climbed into the carriage to make their way to the Mall.

King Charles and Queen Camilla also posted a compilation video, which was shared on the official Royal Family social media accounts, showing the royals piling into their carriages for the procession, the impressive Red Arrows flypast, and King Charles even feeding a carrot to one of the horses pulling the carriage.

In the caption of the video, the King and Queen thanked the military personnel who made the day “truly triumphant”. This year marks the third Trooping the Colour parade of Charles’ reign.

The colour – regimental flag – being trooped this year is the King’s Colour of Number 7 Company Coldstream Guards, also known as the sovereign’s bodyguard and which is celebrating its 375th anniversary this year.