The Duke added: "Do you want me to move out of the photo?"
But Kate got one up on her husband later on in the day. The couple were opening a new recreation facility for military personnel set to be away from their families over Christmas.
Observing its smart new interiors, the Duke told the soldiers to "keep the pizza off the sofas".
To which the Duchess quipped, "You're a nightmare with that".
The couple are well-known for ribbing each other in public. In 2014, at a 'Taste of Norfolk’ charity event, the Duchess told a group of chefs that her husband has to put up with her cooking most of the time, to which the Duke replied: "It’s the reason I’m so skinny".
Similarly, in 2015, on a trip in North Wales, the Duchess was holding her husband's rope as he abseiled down a 12-metre wall, and in the midst of his descent, Kate shouted: "William - how much do you love me?"