The Coronation Concert was enjoyed by millions on Sunday night as some unexpected guests took to the stage.
Fans were delighted as some of the iconic The Muppets characters surprised crowds and delighted fans.
Much-loved puppets including Miss Piggy and Kermit the Frog stole the show when they interrupted Hugh Bonneville and began presenting for the fun-filled skit.
And whilst the King and Queen looked slightly confused at the beginning of the iconic duo's act, William and Kate could be seen looking on amused at their jokes, reports the Mirror.
Brother and sister Princess Charlotte and Prince George were delighted at The Muppets' appearance, as Miss Piggy made her advances on Hugh, whilst George could be seen covering his face and laughing at the strange encounter.
And now, an expert lip reader has disclosed what the Prince and Princess of Wales thought of the segment, which saw Miss Piggy ask Hugh if he was single.
Jacqui Press told the Daily Mail that Kate enjoyed the sketch. Whilst watching the skit, she said: "That's funny!" as she sat next to her daughter Charlotte.
William was also amused by Hugh's joke when he called Miss Piggy the 'pig in a dress' - as he repeated it under his breath with a laugh.
It was a renowned line-up for the celebrations at Windsor Castle, with the likes of Lionel Richie and Andrea Bocelli taking to the stage.
Other famous names including Take That and Katy Perry also performed for UK fans.
Hollywood actor Tom Cruise also sent the new King a message from the cockpit of the plane he was flying.
The Top Gun star told Charles: "Pilot to pilot, Your Majesty, you can be my wingman any time."
The Prince of Wales also took to the stage to pay tribute to his newly-crowned dad.
He began his speech on Sunday with a quip referencing headliner Lionel Richie.
He promised not to "go on all night long", before he shared an emotional tribute to King Charles.
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