July 29, 2013 6:40 PM
Taylor Swift performed a duet with music legend Carly Simon recently. The two performed Simon's classic break-up ballad "You're So Vain". And while the subjects of Swift's break-up songs are very public, Simon remains quiet about her mystery man from the classic song. Rumors suggest it could have been Mick Jagger, Warren Beatty or even music exec David Geffen.