Royal Carol viewers couldn’t help noticing something during the service.

Princess Kate and Charlotte performed together in a piano duet (Image: ITV)

ITV’s Royal Carols viewers couldn’t help mentioning Prince Harry as Princess Kate led the festive music night. In a sweet moment, Kate and Charlotte performed a surprise piano duet during the Christmas Eve celebration as they played “Holm Sound” by Erland Cooper. But another moment during the celebration got people talking, as the choir performed the Sussex Carol. Viewers took to social media to comment on the link to Princess Kate’s brother-in-law Prince Harry, whose title is the Duke of Sussex.

They commented on how “gracious” Princess Kate was to use the carol during her yearly celebration. as one fan said: “Watching Royal Carols: Together At Christmas on @ITVX. Princess Charlotte dueting with Mum. The Sussex Carol (how gracious is our Future Queen!) but …’O Holy Night’? Just blew my head off! Whoa. More to come.”

Another said: “Not gonna lie. Bit surprised with ‘Sussex Carol’,” as they added a side eye emoji.

Fans discussed Prince Harry during the Royal Carols (Image: Getty)

A third asked: “Where’s Harry?” as one shocked fan said: “The choir sang the Sussex Carol,” with a smiley face.

It comes as reports have said that Prince Harry will be spending Christmas with Meghan and their children Archie and Lilibet, rather than with the royals in Sandringham.

A royal expert said to the Mirror about Harry’s Christmas: “Since his marriage to Meghan in 2018, Harry has only had Christmas at Sandringham once in December the same year. Instead, he has embraced the traditions of the ‘happy holidays’ favoured by his adopted country.”

“It would not look good if Meghan who publicises herself as the all-American homemaker was to hire someone to adorn their house and decorate their tree. She will have done it herself and made the gingerbread house as is traditional in America.”

Ingrid added: “Back at Sandringham it will have been the traditional Christmas UK style that Harry knows so well. King Charles would have loved the opportunity to see his grandchildren Archie and Lilibet, but he knew inviting Harry and Meghan would have been awkward for the rest of the family. So, there was no official invitation.

“Harry and Meghan were invited for Christmas at Althorp with thrice-married Uncle Charles, now Earl Spencer, but have decided to stay in California. Meghan says it’s important for her that Archie and Lilibet can have ‘connective memories’ of Thanksgiving and Christmas at home and enjoy the traditions like putting out “carrots for the reindeer.”