Prince Louis placing a note on the Kindness Tree.

Prince Louisis giving thanks this Christmas season.
The youngest son ofKate MiddletonandPrince Williamwrote a sweet message to his grandparents at thefourth annualTogether at Christmascarol serviceon Friday, Dec. 6.
The 6-year-old, who attended the festive event alongside siblingsPrince George, 11, andPrincess Charlotte, 9, placed a note on the “Kindness Tree” set up outside of Westminster Abbey in London, where the holiday event took place.
“Thank you to Granny and Grandpa because they have played games with me,” he wrote on the note, referring to his maternal grandparents, Carole and Michael Middleton.
Prince Louis' messages.Zak Hussein / SplashNews

Zak Hussein / SplashNews
On Sept. 9, the Princess of Wales, 42, announced in an intimate video that she had completed chemotherapy after previously revealing that she was undergoing treatment for cancer in March. In thevideo, which was shared on the official Kensington Royal social media accounts, Kate’s parents can be seen playing games at a table with Louis,Prince George, 11,Princess Charlotte, 9, as well as Prince William, 42, and Kate.
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“Her parents are an enduring factor in the upbringing of their grandchildren,” a palace insider told PEOPLE back in March. The Middletonsreportedly have sleepoverswith the trio of siblings and accompany Kate on school drop-offs occasionally.
Carole Middleton, Michael Middleton, James Middleton, Alizee Thevenet and Pippa Middleton.Samir Hussein/WireImage

Samir Hussein/WireImage
Prince Louis.JORDAN PETTITT/POOL/AFP via Getty

JORDAN PETTITT/POOL/AFP via Getty
Another sweet Louis moment was revealed when Kate Mansey, areporter fromThe Times, overheard Princess Kate speakingto singer-songwriter and actress Paloma Faith. While discussing the ballet performance, which was a surprise revealed during the service, Kate revealed that Louis adorably struggled to keep the surprise a secret from his sister Charlotte, who takes ballet lessons.
“This morning, he said, ‘Mummy, please can I tell her - I’m bursting.’ " the royal holiday host revealed.
Charlotte waseven seenstanding like a ballerina with her feet in third position at one point during the service.
The palace said that 1,600 people would convene in Westminster Abbey on Dec. 6 for the holiday concert, welcoming those who have supported others in their communities through personal relationships, work or volunteering, plus others who experienced difficult times this year.
source: people.com