One Direction heartthrob Harry Styles is reportedly dating model Cara Delevingne.

A source close to Delevingne told E! News that Styles has been dating the model "for around two weeks."

"Harry's been chasing Cara nonstop. He really likes her and has been saying that he wants to be exclusive with her," the insider added.

However, the 22-year-old model is not "sure" yet about their relationship.

Styles "says he wants them to be boyfriend and girlfriend. But right now, Cara is not sure what to do," the source explained, "She's a top girl and she's finding her feet right now. They are seeing each other though, casually, and are actually very cute together. Their friends think it could work out...He's really chasing her, but she's a really busy girl."

The rumour surfaced after Styles was spotted with her to watch a performance of Book of Mormon in London's West End.

"They have great chemistry. Sure, they've always agreed to keep things super-casual and private because of their crazy worlds, but Harry genuinely likes Cara a lot - he has done ever since they met three years ago," a source told Look magazine, "They've actually had an on/off thing going all this time when they're in the same city, but they've never had the chance to give a real relationship a shot. I can't imagine she wants to join the list of women who have been Harry'd.

"Of course he might profess his love for her - and he has done that on many occasions - but she's heard it all before," the insider added, "He said that to her just a month before he went public with Taylor [Swift], so I imagine she's learned her lesson."