ONE DIRECTION are only just out of school so they should be good at drawing intimate parts of the human body.

So it’s no surprise Niall Horan, Louis Tomlinson, Harry Styles, Zayn Malik and Liam Payne are putting in some serious hours playing hit new app Draw Something.

They have been spending downtime on their US promo tour exchanging sketches with loved ones in the UK.

A source said: “The lads are constantly on their phones. It’s not just drawing pictures and sending them to friends and family in the UK, it’s their way of staying in touch.

“Zayn got the lads hooked as he’s a genuinely talented cartoonist.”

One Direction are going to be even busier soon. They have announced a huge gig on December 3 in New York’s Madison Square Garden.

Management went for the gig after tickets for the lads’ North American tour, starting in May, sold out instantly.

Niall said: “To be headlining our own show in a venue that has played host to countless legendary acts that we have grown up listening to and adore is obviously a dream come true for us all.”

The Garden is usually reserved for the top names in music, yet One Direction have so far only released one album and a couple of singles — including Top 3 hit It’s Gotta Be You.