Prince William Smirks as King Charles III Jokes His Grandchildren at State Banquet

Prince William half smiles as King Charles III makes a Pokémon quip and a joke about his grandchildren at banquet.

King Charles III hosted a grand banquet honoring the three-day state visit of Japanese Emperor Naruhito and Empress Masako on Thursday -- where he elicited some laughs while sharing a shoutout to some cultural touchstones of Japan: Pokémon, Hello Kitty and Hayao Miyazaki.

It was during one of these unexpected references that cameras caught Prince William giving his father a smirk of sorts that left people reeling at his seemingly uncomfortable half-smile. During Charles' speech welcoming and praising the emperor, he recounted his experiences spending time with Naruhito in the past -- including fishing together.

"I am only sorry to report that I haven't had any better luck with more recent attempts at fishing," Charles shared, as he read from his prepared speech. "The Pokémon phrase 'gotta catch 'em all' may resonate with my grandchildren, but for me it is, perhaps, aspirational."

King Charles and Emperor Naruhito of Japan share a laugh during the State Banquet at Buckingham Palace on June 25, 2024 in London, England. - Jordan Pettitt - WPA Pool/Getty Images

It was during this Pokémon reference that William seemed to subdue a lot of different feelings all at once -- from laughter to slight embarrassment to surprise -- and the internet was quick to take notice.

"King Charles mentioning Pokemon mid speech was not on my 2024 bingo card," one user commented on X (formerly Twitter).

Another user joked, "Loving #PrinceWilliam’s reaction to #KingCharles #Pokemon joke at the Japanese State Banquet."

Charles also made a special mention of another Japanese cultural export, sharing, "It has been a pleasure to learn of the British stories behind certain Japanese cultural icons."

"Perhaps you would allow me to note one particular individual who turns fifty this year. Raised in a London suburb with her twin sister, a self-made entrepreneur worth billions of dollars, and a U.N.I.C.E.F. Children’s Ambassador on top of all that. So I can only wish a very happy birthday to… Hello Kitty!" Charles declared with delight.

Prince William poses for photos with Japan's Emperor Naruhito and Japan's Empress Masako after greeting them at their hotel in London on June 25, 2024. - Jordan Pettitt - WPA Pool/Getty Images

Charles' references to his grandchildren were of particular delight for some fans. He is grandad to Prince William's three children with Kate Middleton -- Prince George, 10, Princess Charlotte, 9, and Prince Louis, 6 -- as well as to Prince Harry and Meghan Markle's two children -- Archie, 5 and Lilibet, 3.

ET spoke with royal expert Katie Nicholl in May, who explained why Charles -- who was diagnosed with cancer earlier this year -- badly wants to reconnect with Harry, and rebuild his relationship with his grandchildren, who currently live in California.

"He very much wants to be close to his son again and to see more of his grandchildren, who he's barely seen since they were born," Nicholl said. 

"Harry has said that he had hoped that, out of the adversity of his father's illness, he would reunify with the family. It's clearly very much his intention," she added. "My understanding is the king also wants to sort of rekindle his relationship with his son. He loves his son. He's a very forgiving man. I think he certainly wants to move on."

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