Harry Styles is treating his sister to an all-expenses-paid US holiday.

The One Direction hunk has paid for his older sister Gemma, 22, to go on the trip of a lifetime as a present for graduating from Sheffield University in the UK with a First-class degree.

The 19-year-old singer has pulled out all the stops by arranging for his brainbox sibling to enjoy unlimited shopping while she's in America, as well as giving her access-all-areas passes for One Direction's gigs in Ls Vegas in Nevada, and San Diego and Los Angeles in California.

A tour insider told the Daily Star newspaper: ''Harry is giving Gemma a massive treat for getting a first at Sheffield Uni. He's so proud of her as she's worked really hard to get top grades and deserves to have some fun.

''He flew her to Las Vegas and has put her in a posh suite at every stop on the tour with AAA pass access and anything she needs.

''Plus there's a gift of unlimited shopping during her stay in America for clothes and gadgets. He plans to treat her to a new wardrobe.''

The 'Best Song Ever' hitmakers are currently on the North American leg of their worldwide Take Me Home Tour, and Harry is missing his family after being away since the tour left the UK in April.

The source added: ''Gemma loves hanging out with her brother and keeping an eye on him. Harry is in awe of her because she's so brainy and got a first, plus the highest marks in the year.

''He gets homesick sometimes while on tour, so it's great for him to have her there for a while too.''