And, it comes as no surprise as he no doubt has to keep up with his two older siblings, Prince George and Princess Charlotte.
Kate also revealed to the crowds that she would love to take her children to the new V&A museum that she toured in Dundee.
The duchess looked stunning in a recycled Alexander McQueen coat dress and black heels.
Kate made a speech to celebrate the museums opening.
“Last February, I was delighted to become Patron of The V&Ain London,” she said.
“Now, nearly a year later, I’m thrilled to be standing in a brand new V&A; one which has been built for the city of Dundee and for Scotland, and which is already picking up international awards.”