The Duke of Cambridge joked that he was like "giraffe on ice" on a football field during a visit to an academy school in south-east London.
He said: "Watching me on the football field is never a pretty sight – the expression giraffe on ice springs to mind.
"However it is marginally less embarrassing than seeing my brother cheat his way to becoming the fastest man on the planet!
"Catherine, on the other hand, with a tennis racquet or a hockey stick is something to behold and be aware of."
The royals visited the academy school to attend the launch of a new project that is being supported by their charitable Foundation.
More top news
Demonstrators gathered outside the National Press Club to oppose a group of Trump supporters who were staging a "DeploraBall".
Rosalind Brotherton initially started working at a school canteen but after studying part time is now in charge of a primary school.
The unexploded bomb was found near the Houses of Parliament and led to disruption in central London overnight.