Prince Charles flashed a look of mock horror at his wife as he stared at the blade, which was when his entourage and the vineyard’s senior staff erupted with laughter.
The couple are both wine lovers, with Camilla telling Seppeltsfield staff at the time: “I am a red wine drinker. My father was in the wine trade.”
And it is well known that Prince Charles once had his Aston Martin converted to run on biofuel made from wine.
Details of the couple's high-jinx come after Camilla, the Duchess of Cornwall, was photographed attending a service to mark the 75th anniversary of the liberation of Auschwitz in Poland on Monday.
The royal wife of Prince Charles joined the likes of Queen Letizia of Spain, Crown Princess Victoria of Sweden and Queen Maxima of The Netherlands at the service, where she walked 700m alongside the railway lines that brought prisoners to Auschwitz.
The 72-year-old was snapped looking emotional as she wore all black to the service, which was also attended by Polish President Andrzej Duda and Polish First Lady Agata Kornhauser-Duda.
Clarence House later took to Instagram to share a post about the Duchess meeting holocaust survivors Hannah Lewis and Renee Salt.
“The Duchess of Cornwall meets Holocaust survivors Hannah Lewis and Renee Salt following #Auschwitz75 commemorations in Poland today.”
The post continued: “Around 200 Holocaust survivors from across the world joined world leaders at a service today to mark the 75th anniversary of the liberation of Auschwitz-Birkenau, the largest of the Nazi concentration and death camps.”
“On this day in 1945, the Soviet army entered Auschwitz-Birkenau and liberated thousands of prisoners. More than 1.1 million people died at the concentration camp, including nearly 1 million Jews.”