Harry Styles
Harry Styles has reportedly got Nadine Leopold's initials inked on his body. Getty

One Direction star Harry Styles has reportedly got rumoured girlfriend, Victoria's Secret model Nadine Leopold's initials inked on his body.

According to Daily Star, Styles, who recently celebrated his 21st birthday with Leopold is getting serious about their relationship.

"Harry made everyone sign confidentiality agreements so the girl's letters are a secret at the moment," a source said.

"But he had two sets of initials together - 'HS' is one of them of course, but everyone's saying that the other initials are 'NL' – for Nadine Leopold.

"Harry used to go to tattoo parlours when he came to LA. But he gets mobbed so much that he has an artist go to his house instead," the insider added.

The pair first met back in November through the Austrian model's CAA agent Jeff Azoff, and were pictured on a series of dates before Christmas, sparking rumours that they are more than just close friends.

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However, Styles, who has a history of dating high-profile celebrities including Taylor Swift and Kendall Jenner, might not admit about his relationship publicly anytime soon.

"Harry is having a good time being a young rock star," a source told Us Weekly. "You will know he has a girlfriend when he steps out on the red carpet with one. Until then, he's having fun and enjoying life."