It is one of the most enduring mysteries in music: who is the subject of Carly Simon's 1972 hit You're So Vain?
Now the singer has provoked further speculation by performing a "lost" fourth verse in which she sings: "A friend of yours revealed to me / That you'd loved me all the time / Kept it secret from your wives / You believed it was no crime."
That reference to "wives", if it is to be taken literally, rules out several contenders who were either unmarried or only on wife number one when the song came out. They include Mick Jagger, Cat Stevens, Kris Kristofferson and David Geffen, the record mogul.
Instead, it fits the description of another man: Willie Donaldson, a British Lothario who was the first man to break Simon's heart, and whom she described in her 2015 memoir as "a sardonic, adorable, long-legged, coffee-scented charmer". (It may be worth noting that coffee is mentioned in the lyrics of the song.)
To say Donaldson had a colourful life is an understatement. The son of a shipping magnate, he was educated at public school, inherited and spent a fortune, smoked crack and at one point took up residence in a London brothel. He was also the author of the Henry Root letters, a famous literary hoax that saw him write to the great and the good, from Esther Rantzen to Margaret Thatcher and the Archbishop of Canterbury, in the guise of a retired wet fish merchant.