Prince Louis was the star of the show at the Platinum Jubilee concert last summer.
William and Kate's youngest child won hearts with his very animated display – from sticking his tongue out at mum Princess Kate, to pretending to be a lion, jumping seats to sit on grandpa King Charles' lap, waggling his fingers and pouting, and almost falling asleep at the royal event. See his best moments in the funny video below...
So fans were understandably disappointed not to see little Louis in the royal box at Sunday's Coronation Concert.
Parents Prince William and Princess Kate instead just brought along their eldest children, Prince George and Princess Charlotte.
The family were in high spirits as they enjoyed the musical spectacular, along with King Charles, Queen Camilla and the rest of the royal family.
Notably, Princess Anne was also absent, sparking some concern amongst royal watchers.
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So where was little Louis?
It’s most likely that he spent the evening at home with the family’s nanny, Maria Teresa Turrion Borrallo.
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Eagle-eyed viewers watching the coronation service on Saturday noticed that the five-year-old also discreetly made an exit from the two-hour service as a result of his tender years.
It was the first major formal event attended by the youngster, who did not go to his great-grandmother Elizabeth II’s funeral in September.
He did, however, re-join the festivities for the King's Procession back to Buckingham Palace, sitting alongside his siblings and their parents in a horse-drawn carriage.
And once again he had his own shining moment. A clip of the young royal is doing the rounds on TikTok and fans are obsessed.
A lip reader called Kristen Kalvoy claims to have deciphered what Louis is saying in the video as he cups his hands around his mouth and addresses the crowds through the window. She believes he shouts: "What are you yelling to? What are you screaming to?"
However, TikTok users are divided in the comments about what Louis really says in the clip. One claims: "What are you yelling for… what are you screaming for… sounds more like it to me," while another agreed: "feel like 'for' [is] more likely than 'to' and looks similar."
Another queried: "As an English person, don't think he'd use the word 'yelling', that's more of an American-ism but don't think it's far off. He's too cute."
Hundreds of other social media users were smitten with Louis' sweet antics, regardless of the exact wording, branding him a "hoot". One royal fan enthused: "He’s everyone’s favourite."
It was certainly a big day for Louis. And given all the excitement in the hours before, William and Kate likely decided to let him stay at home to unwind away from the public gaze.
He is also set to return to school with George and Charlotte on Tuesday and his parents no doubt wanted him to have some time to get over the weekend festivities before lessons begin.
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