Swift knows she dates 'bad' men

Taylor Swift knows she dates men who are "dangerous" and "bad" for her.

The 23-year-old singer - who is currently romancing One Direction star Harry Styles and has previously been in relationships with Jake Gyllenhaal, Joe Jonas and John Mayer - says her new single 'I Knew You Were Trouble' is inspired by a "toxic relationship" that stems from a good girl falling for a bad boy, and she admits it is based on personal experience.