Gyles Brandreth has quipped that King Charles might have him beheaded for spilling all on his crush on his wife Queen Consort Camilla.
The 74-year-old broadcaster - who was close to the late Prince Philip - thought Camilla looked "gorgeous" in her tight-fitting horse riding pants when he spotted her smoking "behind the bike sheds".
And he's now revealed that when Camilla, 75, met his spouse Michèle Brown many years later, she wanted to clarify that it wasn't a Woodbine cigarette she was puffing on.
Speaking to Best UK, he laughed: "When I had the subject 'My Secret Crush' I began waxing lyrical about how I had met Camilla when she was a teenager.
"I was talking about this gorgeous girl in her jodhpurs smoking a Woodbine behind the bike sheds.
"A while later my wife [Michèle Brown] met the [then] Duchess of Cornwall at a Jubilee event and she said, 'I don't mind your husband telling the story - but tell him it was not a Woodbine!'"
The former politician had joked that he'd probably get in trouble with the king for revealing that he likes to leave answerphone messages to his sons Princes William and Harry "in the style" of the BBC Radio 4 radio comedy panel game 'Just a Minute'.
He said: "The King and Queen Consort were regular listeners.
"When he was Prince of Wales, he did a little message for the programme's anniversary and he revealed that he leaves messages on the answerphones of his sons in the style of 'Just a Minute'."
He quipped: "But of course, I wrote that King Charles ascended the throne, so I might soon be in the Tower having my head removed."