The main conceit of Carly Simon’s 1972 hit single ‘You’re So Vain’ is that the subject of the song would (correctly) assume it was about them, such was their solipsism.

The real weight of the song comes, however, from Simon’s long-held refusal to reveal who the song from actually written about, with theories over the years centering on three main suspects: Warren Beatty, James Taylor, and Mick Jagger, all of whom were involved with Simon at various times.

Many assume the song is about a composite of separate men, and Simon strengthened this theory in 2015, telling People that Beatty was indeed the subject of the second verse – although she quipped that he thought the entire song was, in fact, about him.

Now she has dropped another bomb during a recent BBC documentary, playing an unheard fourth verse, which complicates the story somewhat. The verse introduces multiple wives, suggesting either a long-term affair or some Mormon interactivity. “This is a verse that I haven’t ever sung,” Simon said, before performing the section. “I wrote it a while ago on a pad, but it never made it into the song.”

“A friend of yours revealed to me, that you’d loved me all the time”, the verse begins. “Kept it secret from your wives, you believed it was no crime. You called me once to ask me things I couldn’t quite divine. Maybe that’s why I have tried to dismiss you, tried to dismiss you.”

The plot thickens.