Proud mum Princess Eugenie bounced her young son August on her lap after bringing him to the Jubilee Pageant along with husband Jack Brooksbank.
TV cameras picked up Eugenie holding up the one-year-old as the colourful performers passed by the royal box on The Mall.
And the little boy clearly came dressed for the occasion as he is wearing a very patriotic blue jumper with a Union flag across the front.
At one point he even waved as some of the performers went past before his dad Jack, who was dressed smartly in a suit was seen cuddling his son.
But he wasn't the only youngster in the royal box - also there were Prince George, Princess Charlotte and Prince Louis, who stole the show yet again with a range of facial expressions.
Meanwhile, after the pageant, the Queen delighted Platinum Jubilee revellers by making a much-anticipated Buckingham Palace balcony appearance that set the seal on four days of celebrations.
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Surrounded by her family, the monarch was cheered by thousands of well-wishers after the pageant told the story of her life, and the nation, with an eccentric, fun and imaginative carnival-like display.
Earlier in the day Eugenie and her older sister Princess Beatrice tried their hands at plate spinning and bowls during a surprise appearance at a Jubilee party.
They attended a Big Jubilee Lunch at Paddington Recreation Ground, hosted by Westminster council.
It was one of thousands of similar lunches held across the UK over the Jubilee weekend, with an estimated 15 million people participating in the events.
There they mingled with members of the local community, including NHS workers, a food social enterprise and members of Octavia housing who offer a befriending service for the elderly.
Introducing herself to a table of volunteers and service users from Octavia House, Beatrice said: “My name’s Beatrice, the Queen is my granny, I’m very, very lucky.”
Beatrice then moved to another table with more people from the charity.
She discussed the moment from last night’s concert when the Queen produced a marmalade sandwich from her handbag in a pre-recorded sketch with Paddington Bear at the Platinum Party at the Palace.
“I’ve always wondered what was in her handbag and now we know,” Beatrice said. “The secret is out, it’s a marmalade sandwich.”
The princesses also took time to practise plate spinning.
Circus showman Tim Eagle showed the pair how to spin the plates, with Eugenie receiving a round of applause for her efforts.
