Kate Middleton reveals Prince Louis was forced to keep major secret ahead of rare royal appearance

Kate Middleton has revealed that Prince Louis was forced to keep a major secret from his sister, Princess Charlotte, ahead of her carol service.

Last week (6 December), the Princess of Wales hosted her fourth annual Together at Christmas concert at Westminster Abbey in London.

Kate attended the concert with her husband, Prince William, and their children, Prince George, 11, Princess Charlotte, 9, and Prince Louis, 6.

In a statement, Kensington Palace explained: "This year’s service provides a moment to reflect upon the importance of love and empathy, and how much we need each other, especially in the most difficult times of our lives.

"The service will shine a light on individuals from all over the UK who have shown love, kindness and empathy towards others in their communities."

At the concert, Kate chatted to musician Paloma Faith behind the scenes.

She told the the 'Only Love Can Hurt Like This' singer that 'Louis heard me talk about the dancers over tea'.

"Ballet dancers?" Paloma interjected, while Kate said: "Ballet dancers, exactly.

"So I said, 'Louis, can you keep a secret? I want it to be a surprise for Charlotte, who loves her ballet dancing,' and he said, 'I won't say anything!'. And he's kept the secret, this is what, maybe two weeks? Quite good for a six-year-old!"

Kate revealed she stood with the Together at Christmas performers, which included Olivia Dean and Gregory Porter alongside Paloma.

The mum-of-three continued: "And then this morning he was like, 'Please Mummy can I tell her? I'm bursting!', cause I did the drop off and he really wanted to tell her.

"I think, hopefully, he's kept on with it. I don't think he's said anything. I asked her, just before we left, 'Do you know what the surprise is?' And she said no."

Kate's appearance at the Together at Christmas carol service was the Princess' first major return to royal duties following her cancer diagnosis, which was followed by rounds of chemotherapy.

She shared the news she was cancer-free a few months back in September.

In a statement shared once she had completed chemotherapy, she said: "The last nine months have been incredibly tough for us as a family. Life as you know it can change in an instant and we have had to find a way to navigate the stormy waters and road unknown.

"The cancer journey is complex, scary and unpredictable for everyone, especially those closest to you.

"With humility, it also brings you face to face with your own vulnerabilities in a way you have never considered before, and with that, a new perspective on everything.

"This time has above all reminded William and me to reflect and be grateful for the simple yet important things in life, which so many of us often take for granted. Of simply loving and being loved.

"Although I have finished chemotherapy, my path to healing and full recovery is long and I must continue to take each day as it comes," she said, hinting at what's ahead.

"I am however looking forward to being back at work and undertaking a few more public engagements in the coming months when I can. Despite all that has gone before, I enter this new phase of recovery with a renewed sense of hope and appreciation of life."