A proud Prince William could not contain his joy watching his three children welcome the crowds during the Queen's Platinum Jubilee celebrations.
The Duke of Cambridge broke out into a smile as Prince George, Princess Charlotte and Prince Louis waved to the crowds from Buckingham Palace on Sunday.
Kate Middleton appeared to be on parent duty with youngest Cambridge Prince Louis while his elder siblings took their place in front of dad William.
He was seen beaming as the pair held their hands together in front of them alongside the Queen.
The children were also joined on the royal balcony by their grandad Prince Charles and his wife Camilla, during a surprise appearance by the Queen.
Royal fans were delighted to share in the special family moment and shared their reactions online.
"My heart. How lovely to see Prince William looking proud as he watched his three children," one person tweeted.
"He couldn't contain his smile as he watched them. And it's easy to see how much he adores them."
Another person said: "I never noticed this. This is so beautiful. Such a loving father."
A third added: "I am sure he yearned for a happy, stable family. It is really good to see him like this now."
The royal family appeared on the balcony before the National Anthem played and spent a very short time chatting before red, white and blue smoke popped out of a stage.
Her Majesty "struggled to not be overcome by tears" at the reception and shared her surprise with great grandson Prince George, according to experts.
The Cambridge children delighted crowds throughout the Jubilee weekend when Princess Charlotte made her first royal appearance.
George, eight, and seven-year-old Charlotte were surprise additions to the Duke and Duchess' special visit to Cardiff Castle.
The parents were beaming as their eldest children seemed to take their first official visit to Wales in their stride, while little Louis stayed at home.
Youngest Cambridge Louis stole the nation's hearts at the opening of the Jubilee weekend when he had a pressing question for the Queen.
The four-year-old stole the show as he pulled a series of playful faces and looked hugely excited during an RAF flypast that ended with a spectacular display by the Red Arrows.
At one point Louis could be seen exchanging a few words with his great-grandmother as they waited for the helicopters and planes to fly overhead.
Lipreader Jeremy Freeman told the Mirror how Louis asked: "Are the Red Arrows coming?" To which the Queen replied: "I hope so."
Louis wore a sailor outfit that day, which marked his first official appearance, in a sweet tribute to his dad.
Prince William was dressed in the same clothing at the same event, Trooping The Colour, back in 1985.
The Duke of Cambridge, just three years old at the time, was snapped wearing the nautical look on the balcony at Buckingham Palace.
Prince George also previously wore one of his father's outfits to Trooping The Colour in 2015.