The Duke of Cambridge and Prince Harry have given a rare insight into their life with Princess Diana in a new documentary which will be aired tonight (July 24).
To mark the 20th anniversary of her tragic death, the brothers have gone on camera to speak very frankly about their mother in a bid to keep her memory alive.
In a sneak preview, which was shown on Good Morning Britain, Prince Harry laughingly admitted that his mother was a mischievous parent.
He laughed: "One of her mottos to me was, 'Harry, you can be as naughty as you want, just don't get caught!' She was one of the naughtiest parents."
"She would come and watch us play football and stuff sweets into our socks. I would walk back from a football match and have five packets of Starburst. My whole shirt would be bursting with sweets. When I got back [to school], I would be looking around, open the top box throw all [the sweets into my desk] and lock it up."
Prince William also recounted some of the funnier memories he has of his mother.
Speaking at Kensington Palace, he said: "Just outside this room where we are now, she organized for when I came home from school to have Cindy Crawford, Naomi Campbell and Chrissy Turlington to be waiting at the top of the stairs."
"I was probably a 12 or 13-year-old boy at the time and had posters of them up on my wall. I remember I went bright red and didn't know what to say. I fumbled and pretty much fell down the stairs on the way out."
The documentary's director, Ashley Gething, has revealed that the young royals have never spoken so candidly about their mother before, as we will see in tonight's program.
He also said that it's unlikely they ever will open up to this extent again.
Commenting on the personal moments the princes share in the film, he added: "It is intensely personal, painful at times and an emotional roller coaster."
Diana, Our Mother – Her Life and Legacy is on HBO tonight (Monday, July 24) at 10 p.m.
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