The Cambridges
Kate Middleton and Prince William’s youngest son, Prince Louis, turned eight months old on Sunday. Pictured: Middleton carrying Prince Louis, Prince George, Prince William and Princess Charlotte after Prince Louis’ christening service at the Chapel Royal, St James's Palace, London on July 9, 2018. Getty Images/Dominic Lipinski

Kate Middleton and Prince William’s youngest son has reached another milestone.

On Sunday, Prince Louis turned eight months old, Hello! reported. The youngest member of the royal family was born on April 23. He will be spending his first Christmas with his parents and siblings in Sandringham. The Cambridges will join Queen Elizabeth II in her Norfolk estate with the other members of the firm including Prince Harry and Meghan Markle.

Prince Louis also received his personalized Christmas stocking that matched the stockings of 5-year-old Prince George and 3-year-old Princess Charlotte. Based on this photo, the trio’s sacks are printed with a crown and the words: “Express Mail Service. Please deliver the enclosed presents to George/ Charlotte/ Louis. Delivery date: 25th December.”

Middleton shared a snap of Prince George and Princess Charlotte’s sacks a few Christmases ago. This year, Prince Louis received one, too.

According to Laura O’Callaghan, a journalist for Express, the third-in-line to the throne could be on Santa’s naughty list. Prince George developed a dreadful habit that was presumably passed on by Prince William and Princess Diana.

In an earlier interview, the late Princess of Wales admitted that she couldn’t resist opening presents before Christmas day. The People’s Princess added that any parcel wasn’t safe with her and she feared that Prince William would develop the same dreadful habit because she found wrapping paper undone at home.

Prince George and Princess Charlotte will be opening their Christmas presents a day earlier than most do. The royals don’t open their gifts on Christmas day because they are of German heritage and in Germany, gifts are exchanged on Dec. 24.

Queen Elizabeth II has three strict rules when the royals exchange gifts. First, the Queen requires everyone to not open their present until Prince Philip gives his permission as the Duke of Edinburgh supervises the event. Second, every present should be cheap and funny. And third, the cheaper the present one gives, the better.

Sunday Express editor and columnist Martin Townsend warned the Duchess of Sussex about these rules. According to him, Markle will be in big trouble if she doesn’t follow the tradition. However, it seems that there’s nothing to worry about since this is not the first time Markle will be joining the royal family for Christmas.

Markle spent the holidays with Prince Harry and the rest of the members of the Firm last year. She gave the Queen a singing hamster and the monarch was in hysterics after receiving it.