As Wimbledon heads into its second week, royal watchers and tennis fans alike are revisiting some of the most memorable moments the tournament has offered—not all of them happening on court.

Among the standout memories is a charming exchange between tennis legend Roger Federer and the Princess of Wales, Kate Middleton, which took place during the 2023 championship. The moment—caught on camera and widely shared—sparked conversation not for its glamour, but for a subtle break from royal etiquette.

Federer, a guest in Wimbledon’s prestigious Royal Box, was seated beside the Princess as they watched Elena Rybakina take on American player Shelby Rogers. At one point, Federer appeared to lean in to kiss Kate on the cheek while placing a hand gently on her back—an affectionate gesture more typical between friends than royals and guests.

According to long-standing royal protocol, members of the royal family should not be touched unless they initiate physical contact, typically in the form of a handshake. But in this case, the interaction seemed entirely natural, even welcome.

Federer and the Waleses have known each other for years. The Swiss athlete once gave Prince George a private tennis lesson and has often spoken about Kate’s love for the sport. “It was so fun sitting next to Princess Catherine,” Federer shared in an interview at the time. “She’s an avid tennis fan and she plays herself. Sometimes we have to be careful not to chat too much between points.”