Princess Diana was known for a lot of things - her style, being a devoted mother and her cheeky sense of humour.
A 'secret' rude birthday card she gave to a friend has been revealed, and it shows just how naughty she could be.
The card came to light after it was put up for auction, with an estimated worth of £600-£900.
The front of the card shows a woman asleep in bed with the caption: "A little prick in the hand sent Sleeping Beauty to sleep."
And the message inside the card, which is hand-signed by Diana, is very rude.
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It reads: "Only the big ones are worth staying awake for!"
Diana's message reads: "Tony, a belated Happy Birthday for the 5th. From, Diana."
The seller, who asked to remain anonymous, told Mirror Online: "I was shocked and surprised when I first saw the message in the card, because I always knew that Princess Diana had a cheeky sense of humour but I had no idea that it was to this extent.
"Her sense of humour was actually flirty and naughty judging by the text in this card.
"I know that Diana liked to send humorous cards, but I haven't seen any quite this naughty, so for me, it really shows that she was a fun human being that could share some dirty jokes with her closest friends.
"I also think that Diana wasn't that innocent at all! I mean, come on look at this card.
"She was quite the naughty Princess that wanted to cross boundaries and play on the dark side.
"This is a secret card that has been kept hidden for many years. A true gem for anyone that is a fan of this special human being."
The owner had got the card from a Diana collector but decided to sell it on.
The card was put up for sale on Julien's Auctions, with an estimated sale price of between $800 and $1,200 (£600-£900).
The starting price was $200, approximately £147, but it completely exceeded expectations and was purchased for a staggering $2,560, which works out to be £1,886.
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