Prince Louis put on a cheeky display while attending a Christmas concert organised by his mother, the Princess of Wales.
The young royal was pictured blowing out his sister Charlotte’s candle at Kate’s Together At Christmas carol service at Westminster Abbey attended by his family and other royals and celebrities.
Louis, five, Charlotte, eight, and elder brother George, 10, made a rare public appearance at the annual event, which celebrates those supporting youngsters and families and featured a reading by Oscar winner Jim Broadbent and singers Beverley Knight and Adam Lambert.
As they walked into the abbey, the royal children posted Christmas cards, in a special postbox, containing messages for children who might be struggling this Christmas, something open to all youngsters attending.
The trio carried candles, as did other children, and at one point, Louis reached across and extinguished a smiling Charlotte’s candle.
Former Beatle, John Lennon, and George Michael, were celebrated 43 years to the day that Lennon was shot dead, aged 40, outside his New York apartment.
Among the highlights of the service was songwriter and multi-instrumentalist Jacob Collier playing Wham!’s hit Last Christmas on John Lennon’s piano, which belonged to Wham! singer and later solo star George Michael and loaned by his estate.
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Broadcaster Roman Kemp, the son of Spandau Ballet bassist Martin Kemp and former Wham! backing singer Shirlie Kemp, introduced Collier and talked about the role Michael, who was his godfather, played in his life.
Among the guests were the Duchess of Edinburgh, Princesses Beatrice and Eugenie, Zara Tindall, Peter Phillips and his daughters Savannah and Isla.
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Kate got to the abbey before the service started in order to meet the performers and she thanked Broadbent reading an extract from Letters From Father Christmas by Lord Of The Rings author JRR Tolkien.
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She also walked around the Abbey before the event began, speaking to young people who have done inspiring activities.
Kate met seven-year-old Oscar Burrow, from Lancaster, who, when aged six, climbed 12 mountains raising more than £40,000 for a children’s hospice.
His mother Kimberley Burrow said Kate “had heard about what he’s done and he’s doing a fantastic job, and hopes what he’s doing will inspire other children to do amazing things.”
Once In Royal David’s City opened the service and Knight and Lambert sang Nat King Cole’s The Christmas Song.
The event will be on television on Christmas Eve.