Taylor Swift has reportedly realised she only ever had a crush on Harry Styles.

The US singer enjoyed a brief romance with the One Direction heartthrob at the end of 2012, with her hit I Knew You Were Trouble said to be about him.

Although things aren't thought to have ended well - they reportedly went their separate ways after a huge argument in January 2013 - there have been rumours about the pair pining for each other. But now Taylor has moved on with DJ Calvin Harris, she's apparently realised the truth about her infatuation.

"Taylor once thought she loved Harry, but since getting to know Calvin, she's realised that Harry was never really more than a crush. The relationship was not nearly as serious as she thought it was at the time," a source told British magazine Heat.

Taylor and Calvin were first linked at the Brit Awards in February and since then have been spotted together in Las Vegas and shopping for food. She has even introduced him to her parents, and it's apparently Calvin who's taught her what she wants in a relationship.

"Taylor was more than happy to delete Harry's number. Calvin's made her realise that boys like Harry are toxic for her and given her the confidence to cut him out of her life for good. She's determined to show Calvin she's serious about him and wants him to feel as secure as she does," the source said.

It's suggested there are other reasons why the new couple are getting on so well. According to psychic astrologer Michelle Knight, it's written in the stars.

"Calvin is a grounded Capricorn, while Taylor is a free-spirited Sagittarius. He feels he's only been around people-pleasers, so he loves that she speaks her mind. And Tay wants a strong man like Calvin," she told the publication.