Because it felt very fragile, it felt very tentative. ' " But Taylor, who is now dating Scottish DJ Calvin Harris, insists their short-lived relationship, which also inspired several other tracks on her most recent album '1989,' still meant a lot to her.
To review all the gushy details, MTV News is taking a look back at Haylor's history.
Sparks, and speculation, began to fly at the 2012 Kids Choice Awards, where Swift and Styles met backstage.
During One Direction's performance of "What Makes You Beautiful," Swift was seen dancing and singing alongside best friend Selena Gomez.
In an interview with the Daily Mirror, mutual pal Justin Bieber got the rumor mill spinning when he revealed that "one of the biggest artists in the world thinks Harry is so hot, but I have been sworn to secrecy." Shortly after, MTV News caught up with the boys and to Harry's apparent embarrassment, hinted that something might be going on between the two.
Taylor Swift felt anxious throughout her relationship with Harry Styles.
The Bad Blood hitmaker has admitted she never really felt like their romance would last because they were constantly facing obstacles.
The couple split in early 2013 after just three months of dating.
Before performing an acoustic version of her track Out of the Woods which is believed to be about her British ex-boyfriend, the 25-year-old singer said: "The number one feeling I felt in the whole relationship was anxiety.
Things cooled off in the summer months between Styles and Swift, who, at the time, was linked to 18-year-old Connor Kennedy.