The One Who Really Broke Taylor's Heart? Jake Gyllenhaal

Taylor Swift has written a lot of sad songs about a lot of guys, but an insider tells Radar that Jake Gyllenhaal is the one who really did a number on her, leaving her "damaged goods." Swift was originally "saving herself for marriage" but ended up losing her virginity to Gyllenhaal after just three months together, the source claims. Shortly thereafter, the actor failed to show up to Swift's 21st birthday party, leaving the singer to lock herself in the bathroom and cry all night. (And later, of course, write a song, "The Moment I Knew," based on the experience.)

"She thought she was going to marry Jake, that’s how in love she was with him," the source says. "Her breakup with Jake inspired every word of [her album] RED." The source claims Swift is still "stuck" on Gyllenhaal; if so, we've got bad news for her: The New York Daily News reports that it's looking like he's back together with his most recent ex-girlfriend, model Alyssa Miller. (More Taylor Swift stories.)