King Charles roasts himself over his own 'sausage fingers' to Prince William

King Charles has shown off his humorous side after poking fun at his medical 'sausage fingers' condition in a new documentary.

Charles III: The Coronation Year is the title of a new BBC documentary, set to give us a behind-the-scenes look at rehearsals for the coronation.

The documentary shows us how everything is readied ahead of the big day.

From alterations to the crown jewels, the work of the Royal School of Needlework, and the arrival of the King and Queen’s anointing oil from the Holy Land.

The 90 minute film - set to be screened on Boxing Day - shows the King and William rehearsing with one another, showcasing a lot of affection between father and son.

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In one scene, William tickles his dad’s left cheek, making him laugh, then kisses him on the right cheek.

But the King questions the move saying: “Wasn’t it that side?,” pointing to his other cheek."

William also makes the senior clerics and officials around him laugh when he says to his father 'your left cheek is better', after kissing it and giving his face another affectionate stroke.

Elsewhere in the doc, William was filmed closing a small clasp on the robe wrapped around his father, which again made the King laugh.

William joked: “On the day, that’s not going to go in.”

Charles replied with a smile, adding: “No, you haven’t got sausage fingers like mine.”

Also, when he was the Prince of Wales, Charles would reportedly poke fun at his 'sausage fingers' that often go viral on social media.

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And in a letter to a friend after William was born, Charles reportedly wrote: “I can’t tell you how excited and proud I am.

“He really does look surprisingly appetising and has sausage fingers just like mine.”

GP Chun Tang, Medical Director at Pall Mall Medical in Manchester, has since shed some light on the medical condition.

Dr Tang told the Daily Mail: "Often puffy fingers are a symptom of water retention which can be caused by numerous health conditions.

"This condition arises due to inflammation and can be a result of arthritis, multiple bacterial infections or even TB.

"Other possibilities include high salt levels, allergic reactions, medicinal side effects, injury and autoimmune disease."

Charles III: The Coronation Year will be screened on Boxing Day at 6.50pm on BBC One and iPlayer.