'You're So Vain': Taylor Swift explains Carly Simon duet

Taylor Swift knows a thing or two about writing breakup songs, so it's no surprise that she decided to partner with the queen of the breakup anthem, Carly Simon, when she recently stopped her Red tour at Foxboro, Mass.'s Gillette Stadium. Swift and Simon sang a duet of "You're So Vain" that took the house down, and now the two women have come forward to explain a bit of their affection for one another.

"When I heard 'You're So Vain,' I just thought, 'That is the best song that has ever been written,' " Swift says in behind-the-scenes footage from the concert. "That is the most direct way anyone has ever addressed a breakup. It's amazing."

Simon adds, "It's a song that really that really developed that style of mine. A lot of it was not knowing that I was developing that style."

After the concert, Simon couldn't stop gushing about the experience of singing with Swift. "It was just so wonderful that I just want to do it again," Simon says. "She was so great, and she really led me through my own song. She was just so loving of the whole thing and we loved each other and moved together and apart. It was dramatic. It was so great."

The best gift of all for Swift? Simon allegedly told her who "You're So Vain" is written about.

Watch the full performance below:

Photo/Video credit: MTV/YouTube/Getty Images