Princess’ penchant for raunchy sex jokes revealed

The People’s Princess evidently had a naughty side.

Letters that Princess Diana had written to Constantine II, the last king of Greece, went up for sale at the Dominic Winter Auctioneers auction house.

The secret notes were full of sexual undertones and cheeky, NSFW jokes that the late royal had penned to the monarch, who died earlier this year.

The two cards were sold on May 17 for a bid of $7,000.

The risqué pamphlets, published by the GirlsTalk card series around the year 1987, each contained a humorous adult cartoon with a racy punchline.

The first note reads: “Adam came first … Men always do!”

The picture on the card’s front showed an illustrated, naked blond man with a leaf covering his private areas — à la the Bible’s first man, Adam.

The other letter featured a woman wearing just a bra and underwear, while looking shocked. The top of a man’s head is shown masking her genital arena.

Its caption read: “What’s the definition of the Perfect Man? A midget with a 10″ tongue who can breathe through his ears!”

Both notes were signed in Diana’s signature loopy letters and each had a special message scribed to the king.

“Dearest Tino, fondest love as always, from Diana,” one card said.

The second memo noted: “Dearest Tino, lots of love from Diana. I couldn’t decide which card to send [and] then thought you’d enjoy both!”

According to the auction house’s website, the reason the Princess of Wales sent her letters are unclear.

“The cards do not celebrate a birthday, Christmas or christening,” the product description reads. “Diana must have seen these cards and thought of Tino before buying and sending them, possibly inspired by a conversation they had had at some social gathering.”

Constantine, also known as Tino, ruled Greece from 1964 until 1973, when the monarchy was abolished.

He had ties to the British royal family, being the first cousin once removed from Queen Elizabeth’s husband, Prince Philip.

Constantine was also the godfather of Diana’s eldest son, Prince William, while Philip and Diana were later named godparents to the youngest son of Tino and Anne-Marie of Denmark, Prince Philippos of Greece and Denmark, born 1986.

Diana was married to the now-King Charles from 1981 until 1996, and died in a car crash in 1997, shortly after the royal pair’s separation.

Charles, 74, was formally crowned as Britain’s sovereign on May 6 at Westminster Abbey alongside wife Queen Camilla.

However, many fans still held Diana in their hearts on that joyous day, remembering her as the “real queen.”

People took to Twitter to gush over Diana, with one writing: “The real Queen of Great Britain will always be Diana #CharlesIII #Coronation.”

“The Queen we never had. What a sad sad story. The Queen of all our Hearts. #Coronation,” someone else added.