Kate Middleton's five-word remark about Prince William to Princess Charlotte during rare public appearance revealed by lip reader

It's fair to say that Prince George, Princess Charlotte and Prince Louis stole the show over the bank holiday weekend.

The royal family were in attendance at this year's VE Day celebrations, with the children - who attended with their parents, the Prince and Princess of Wales - delighting viewers with their cheeky antics.

Especially Prince Louis, who was spotted rolling his eyes and flicking his hair like his older brother in a hilarious viral moment.

The British event commemorated 80 years since Germany's surrender in WWII was accepted, and saw the royal family-of-five seated together on the balcony of Buckingham Palace.

Since the event, lip readers have been commenting on some of the royals' interactions, including a sweet moment between Kate and Charlotte, in which Kate makes a cute remark about husband, William.

Kate made a sweet comment to Charlotte (Samir Hussein/WireImage)

Lip reading expert Nicola Hickling told The Sun that Kate asked her daughter: "Doesn't papa look smart today?"

Hickling also interpreted a moment between Prince Louis and Prince William, moments after the youngster was seen brushing raindrops off his dad's shoulder.

Shortly afterwards, the dad-of-three to turn towards him and seemingly give him a tap on the leg.

The pair then exchanged a few words together, with Hickling revealing that William told Louis: "Look at this I think it's going to be quite wet today."

According to the outlet, Louis then asked a savage six-word question to William: "Wasn't this supposed to be fun?"

"It is son," William reportedly replied, also saying 'you will never forget this' before explaining how the parade will work.

Prince Louis stole the show (Neil Mockford/GC Images)

"They will come along here, and then go towards there, and then we will make our way back," he said.

William reportedly added: "It's not going to be long and I want you to be taking an interest."

During Sky News’ footage, a camera focused on the siblings as George went to fix his hair, running his fingers through his locks to move it out of his face.

Moments later, Louis then appeared to mimic him, with an obvious display of exaggeration - a gesture which has sent many royal fans rushing to social media to share their reactions.

One wrote: "This is brilliant! mimicking his brother! No hair in his face but he’ll brush it away just to be like him!"

While another said: "Absolute character. Love Louis."

And a third added: "Everybody loves Prince Louis as well as the all royal family. But he is definitely the most funny one."