|One Direction's Harry Styles|
The 18-year-old One Direction star was spotted holding hands with the 22-year-old country singer at her rehearsals for 'The X Factor' USA last Thursday but he reportedly still isn't ready to commit to her despite already breaking her heart once this year.
A source close to Harry told gossip website RadarOnline.com: "Taylor and Harry have been quietly seeing each other again. When Taylor dates someone she jumps in full force, but Harry is being a little more cautious this time around.
"Taylor is a hopeless romantic, so she's really hoping it works out with Harry. Harry's being really sweet with her right now and careful not to hurt her. But at the same time, he's a young, popular heartthrob who isn't quite ready to be tied down."
The couple are said to have briefly dated in April but parted ways after she saw photos of him kissing American model Emma Ostilly in Australia.
The insider said: "Taylor really liked Harry and even though they weren't exclusive, he hinted at making it official with her just before he took off to Australia... [one morning ] Taylor had all these texts from Harry begging for a chance to explain and telling her not to believe everything she read.
"She immediately googled Harry and found all the stories and pictures of him kissing Emma. She was heartbroken."
Meanwhile, Simon Cowell has given their romance his blessing.
The 53-year-old 'The X Factor' judge said: "I wasn't at rehearsal, but heard about it when I came down. I think they are good together."