Guests at the Princess of Wales's Christmas carol service were treated to a magical evening at Westminster Abbey on 6 December, and it seems that Kate's children were also left enchanted by the performances.
The Together at Christmas concert was broadcast on TV on Christmas Eve, and viewers got to see the young royals' reactions as they took their seats inside the London church.
There were a number of celebrity guests in attendance, including actor Richard E Grant, who captivated the audience as he read a passage from A Christmas Carol by Charles Dickens.
Princess Charlotte, nine, and Prince Louis, six, both giggled and smiled as the Persuasion star brought the characters of Scrooge and Tiny Tim to life with his voices and expressions.
At one point Charlotte turned to smile at her mother Kate, while Louis and his big brother, Prince George, 11, both grinned.
Charlotte also appeared mesmerised by a performance from the Royal Ballet School – a surprise that Kate asked her young son Louis to keep secret from his sister, who is renowned for her love of dance.
Speaking to singer Paloma Faith ahead of the service, the Princess of Wales told Paloma Faith of Louis: "He has kept the secret for, what, nearly two weeks now."
"Very challenging," Paloma agreed.
“For a six-year-old," replied Kate. "And then this morning he said 'Mummy, please can I tell her – I'm bursting'. I did drop off and he really wanted to tell her. I think - hopefully – he's kept it."
George, Charlotte and Louis arrived with their father, the Prince of Wales, at the carol service in London, with their mother Kate greeting them outside the Abbey.
The three young royals stopped to place personal messages on the Kindness Tree, with Louis' handwritten note dedicated to his maternal grandparents, Carole and Michael Middleton. It read: "Thank you to granny and grandpa because they have played games with me."
The Middletons were in attendance at the concert, with Kate sharing a sweet moment with her doting mother Carole.
The Princess' siblings, Pippa Matthews, and James Middleton and his wife, Alizee, were also among the guests, along with members of the royal family.