by Claudine Zap So singer-songwriter Carly Simon has finally let out her deep, dark, secret . Sort of. (More on that later.) According to a UK tabloid , the mysterious figure who is the center of her song " You're So Vain " is not ex-boyfriend Warren Beatty . Nor former flames (and, we assume vanity-hogs) Mick Jagger , Cat Stevens , or Kris Kristofferson . In fact, the vain guy wasn't a lover at all.