John Mayer and Taylor Swift perform onstage during Z100's Jingle Ball 2009 presented by H&M at Madison Square Garden on December 11, 2009 in New York City. (Photo by Theo Wargo/WireImage)
John Mayer and Taylor Swift perform onstage during Z100's Jingle Ball 2009 presented by H&M at Madison Square Garden on December 11, 2009 in New York City. (Photo by Theo Wargo/WireImage)