Why Prince Louis is wearing tights while Prince George is wearing trousers for the first time in an official portrait

Prince Louis is wearing tights for his first official Christmas card, while big brother George has ditched his traditional shorts and this is why...

Just in time for Christmas, the Cambridges have released a brand new family picture, taken at Anmer Hall.

In the new snap, Kate and Wills' little ones look adorable, with Charlotte and George standing on a tree trunk while mum and dad sit on it and Kate holds Louis in her arms.

Royal fans are loving the family's casual look, with one saying: 'They look like such a normal family. I know both Will and Kate always wanted their kids to have a normal childhood. Also look at them muddly Wellies! Can't deal.'

Another said: 'How great to see Prince George in jeans and wellies instead of short trousers all the time. Lovely picture'.

But other eagle-eyed fans spotted a very big difference between this portrait and previous pictures of the family - George is not wearing shorts!

One royal fan said: 'How great to see Prince George in jeans and wellies instead of short trousers all the time.'

The future king is often pictured in short and socks, apart from when he was a pageboy at his uncle Harry's wedding in May.

According to royal tradition, Prince George had to wear shorts until he was older so means he's officially a big boy now!

Etiquette expert William Hanson previously told Harpers Bazaar: 'It's a very English thing to dress a young boy in shorts.

'Trousers are for older boys and men, whereas shorts on young boys is one of those silent class markers that we have in England.

'Although times are (slowly) changing, a pair of trousers on a young boy is considered quite middle class – quite suburban. And no self-respecting aristo or royal would want to be considered suburban. Even the Duchess of Cambridge.'

Read more: Kensington Palace shares unseen photo from Prince Harry and Meghan Markle’s wedding for Christmas card

But if George had to wear shorts until now, why is Louis wearing tights?

Prince George wore shorts in all previous Christmas cards

Some people have suggested it could because the picture was taken in autumn, when it's cold and he's very young to be exposed to cold temperatures.

Prince George has been snapped for a previous Christmas card in the autumn outside while dressed in shorts, but he was a bit older by then.

Either way, they both look adorable alongside sister Charlotte!