In the footage, Charles explained: “We really wanted to win.
“And I get this usual stuff, ‘silly old father, get on with it’, kind of thing.”
William interjected: “That was the politest thing I said.”
Charles said: “I was trying too hard, I remember, I had to turn the pony very fast.
"The next thing, the pony came down, so I must have landed absolutely on my head.
“Anyway, it completely felled me. I ended up being taken to hospital.
“When I finally woke up, this person here [pointed to Harry], told me later that he thought when I was lying on the ground.
“He thought, ‘Oh Papa’s just snoring’!”
Charles added: “There I was, busily swallowing my tongue, quietly dying!”
There was laughter from both Harry, William and Ant and Dec before Charles continued: “Can you imagine, they tried to kill me so they could walk off with my ponies!”
Harry interrupted with a smile: “And the rest!”
William added that they worked very well as a team, but when one of them did something wrong there were always “two very stern faces looking at you”.
“And then you get the b*ll*ck*ng afterwards!” he explained.
It's not known when the three princes will be seen together again after Harry stepped down from his royal role and moved to Canada.
The COVID-19 crisis is also keeping the royals apart.
