Taylor Swift has insisted she is OK with her musician ex-boyfriends, including Harry Styles and John Mayer, writing songs about her because she has penned so many tracks about her love life.The 'I Knew You Were Trouble' singer - who has dated a string of stars including One Direction heartthrob Harry Styles, John Mayer and Jake Gyllenhaal - is well known for pouring her heartbreak into the lyrics of her songs, and insists it's OK for her former lovers to do the same.In an interview with the latest UK issue of InStyle magazine, she said: "If I'm gonna write songs about my exes they can write songs about me. That's how it works. I'm not gonna complain about it"I'm not gonna sit there and say, 'I'm the only one who can write songs about this relationship.' It's fair game."The 23-year-old country star's latest chart-topping album, 'Red', is largely thought to feature songs about 'Jarhead' actor Jake, 32, while 'I knew You Were Trouble' is about her first split from Harry.Â Taylor performed the track at the BRIT Awards on Wednesday night (20.02.13) as Harry, 19, looked on in the audience.She avoided seeing him backstage and organisers did their best to keep them apart throughout the night.Â A source said: "Taylor and her people passed Harry backstage and a security guard barked, 'Look left!' so there was no eye contact."Harry, however, complimented his former girlfriend's show-stopping performance at the BRITs, where she ripped off a conservative white wedding dress and gyrated on stage in a sexy black and lace outfit.