Cheeky! One Direction's Harry Styles grabs Zayn Malik's crotch backstage at Atlanta concert
Harry Styles and Zayn Malik aren't afraid to joke with each other
One Direction are on the US leg of their Take Me Home world tour
Harry Styles is loving entertaining crowds in America
Zayn Malik has a gruelling tour schedule
Louis Tomlinson has assured fans that One Direction's documentary film isn't scripted
The singer, 19, grabbed Zayn's crotch through his trousers at their show in Atlanta, Georgia on Friday.
In a photo of the very personal moment, Zayn, 20, doesn't look too bothered and pulls a mock surprised face as he puts his hand over Harry's.
The Bradford-born star is dressed very casually in tracksuit bottoms, a baggy top and a white cap, while Harry shows off a very tanned arm in a grey vest.
This isn't the first time in recent days that Harry and Zayn have got jokey with each other.
Last week, Zayn cheekily ate a sweet from an edible thong that curly-haired heartthrob Harry had put on during their concert in Columbus, Ohio.
The 1D lads love messing around and often pull pranks - something which is likely to have been filmed for their documentary movie This Is Us, which is set for release in August.
'Nothing at all was scripted. You know if we are asked the questions... we just answer naturally,' Louis Tomlinson, 21, tells Total Film.
'Because I think that's the most important part, that we show people who we are. And you know, to do that we can't have anything scripted. So it's all a reality.'
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