The "I Knew You Were Trouble" songstress was allegedly completely left devastated when Jake Gyllenhaal did not even show up to her 21st birthday-even when the Grammy-nominated singer gave her virginity to the "Brokeback Mountain" star. The snubbing of Taylor Swift's 21st birthday apparently left the singer to tears in the bathroom-that's how grave the breakup must have been.

Well, at least something good came out of it as the singer apparently made her make the award-winning song "Red." Makes pretty sense when you look at the lyrics such as "event," "party dress" and "tears are streaming down your face in front of everyone you know"-all references to the snubbed 21st birthday of the chanteuse.

We all know that Taylor Swift has announced publicly that she wanted to save "it" for her honeymoon. Guess she thought Jake Gyllenhaal was the man whom she was going to face at the altar. The chanteuse broke her ground rules for the "Brokeback Mountain" only to be left by the "Prisoners" actor. A close source revealed that, "she thought she was going to marry Jake, that's how in love she was with him."

The source revealed that everything was set for the singer's 21st birthday-only one person was amiss, that is, no other than Jake Gyllenhaal. According to Perez Hilton, "Taylor thought maybe he was planning some sort of surprise. Nope. He didn't show up and she locked herself in the bathroom and cried the entire night."

Finally to drive the nail into the coffin about this Swift-Gyllenhaal issue, the source revealed that, "Her breakup with Jake inspired every word of RED. The song that specifically references this 'event' is 'The Moment I Knew.' The lyrics are all about her birthday party and Jake not showing up."

Swift is notorious for making up songs with all her ex-flings. It is said that her song "Dear John" was for her former love affair, John Mayer, who is currently reported to have popped THE question of marriage to pop star Katy Perry. The award-winning song "I Knew You Were Trouble" is allegedly for One Direction singer Harry Styles.