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
The prime minister reached a compromise deal within Tory ranks in a bid to prevent a revolt over plans to write the Brexit date in law.
Freezing, frosty and icy again tonight as temperatures fall.
Fashion giant Michael Kors Holdings announces that it is phasing out real fur over the next year.