The famously cheeky Prince Louis might rub his brother off if Prince George sticks his tongue out at Sandringham.
Earlier, Prince Louis lovingly held hands with his second cousin Mia, nine, as he joined the rest of the royal family on Christmas Day.
But Prince George, 10, looked admirably mischievous as he stuck out his tongue as he arrived at St Mary Magdalene Church with his family.
Little Louis, five, was joined by Prince George and Princess Charlotte, eight, and his mother and father at the royal residence.
Royal Christmas holidays traditionally include greeting people outside the church, and a family lunch with turkey and all the trimmings.
Sandringham House has been the private home of four generations of British monarchs for more than 160 years and is now owned by the King.
Prince George is sticking his tongue out at Sandringham today
Prince George, wearing a navy blue suit, walked next to his sister
From left to right: Queen Camilla, Prince Louis, Prince George and King Charles attend the Christmas Day morning church service at St. Mary Magdalene Church in Sandringham
Prince George, William, Prince of Wales, Princess Charlotte, Mia Tindall and Kate, Princess of Wales meet well-wishers after attending the Christmas Day service at St Mary Magdalene Church in Sandringham
Normally little Louis steals the show with his cheeky antics, but today it was his older brother, perhaps influenced by his sibling.
Earlier this month, Prince Louis brutally blew out his sister's candle during Kate's annual Christmas carol concert, leaving his royal sibling in hot water.
He was depicted puffing up his cheeks in an attempt to extinguish his older sister's candle as she smiled.
The royal family enjoyed their annual Christmas walk at Sandringham today.
King Charles was accompanied by Camilla, the Queen Consort, at the head of the group, with the Waleses walking close behind them alongside their three children.
Adorable Prince Louis – who often steals the spotlight with his cheeky display – took part in his first ever Christmas walk last year.
Today he opted for tweed trousers and a navy blue jacket.
The Princess of Wales beamed with happiness as she walked to the service with her husband, ahead of the other members of the royal family.
The Prince and Princess of Wales attend church with their children, Princess Charlotte and Prince George, who held Mia Tindall's hand
The Princess Royal arrives at the church for the morning service at Sandringham
Prince Andrew and his ex-wife Sarah Ferguson put on a united front as the royal family enjoyed their annual Christmas walk at Sandringham
Louis held the hand of his cousin Mia as they walked into the church service at Sandringham
She looked elegant in her festive outfit as she waved to well-wishers who traveled to Norfolk today.
Prince Andrew and his ex-wife Sarah Ferguson presented a united front as they walked behind royals as the crowd lined the road outside St Mary Magdalene Church for the traditional Christmas Day service at the Norfolk estate.
It is the first time in more than three decades that Fergie has joined the royals for the walk, following the couple's high-profile divorce in 1996.
But King Charles softened that approach last year and invited her to join the family at Sandringham for the first time in decades, even though she did not attend church.
Andrew's daughters were with their husbands, Princess Beatrice with Edoardo Mapelli Mozzi and Prince Eugenie with Jack Brooksbank.
The private Norfolk estate once again saw the traditional royal festivities, with most of the family in attendance – except for the Duke and Duchess of Sussex, who are spending the day in LA with their children, Prince Louis and Princess Lilibet.
King Charles was seen waving to the crowds gathered outside Norfolk Church to wish him and his family well this Christmas as he walked alongside Queen Camilla.
King Charles was seen waving to the crowds gathered outside Norfolk Church to wish him and his family well this Christmas as he walked alongside Queen Camilla.
Catherine, Princess of Wales, attends the Christmas Day service with Prince George of Wales and Prince Louis of Wales
Princess Charlotte also joined her brother Prince Louis as they entered the church today
The Princess of Wales smiled broadly as she walked to the church wearing an elegant blue coat and matching hat, holding her daughter Princess Charlotte's hand.
Her younger brother, Prince Louis, joined the rest of his family and held Mia Tindall's hand as they prepared to attend the service.
On his other side, Prince William also held his son's hand, while Prince George, dressed in a navy blue suit, walked alongside his sister.
The Duke and Duchess of Edinburgh joined the rest of the royal family on their way to church.
The royal festivities usually start when everyone arrives on Christmas Eve. The family opens presents, some of which are gag presents – one of the royal family's traditions.
The family then attends services at St. Mary Magdalene Church on Christmas morning. Once they get home, a Christmas lunch is served, followed by games in the afternoon.
Last Christmas the royals experienced their biggest change in decades as they celebrated their first festive period without Queen Elizabeth II, who had died just a few months earlier.