Boy Band ‘One Direction’ on Tattoos, Girlfriends

ABC News Nightline
Nightline Fix

Every generation of girls has one – a boy band which rocks the heart of an era. In this moment, that band is One Direction.

So big, they did something even The Beatles didn’t do. They hit No. 1 in the United States with their first album.

"Nightline" went behind the scenes -- and in their dressing room -- with Niall Horan, Liam Payne and Harry Styles, all 19 years old, Zayn Malik, 20, and Louis Tomlinson, the oldest at 21, on Sunday as they were getting ready for the MTV Video Music Awards -- complete with funny moments, from Styles as he hits the shower and a shot of Horan's abs.

They say they are trying to do it their way. No matching outfits. No dancing. And so far, it’s working. They just wound up their sold-out world tour. And won a VMA for their summer hit “Best Song Ever.”

Three years ago, Harry was sweeping up in a bakery and Louis worked at Toys “R” Us. They were just five kids hoping for a break on the British reality show “The X Factor.” After being booted as solo artists, their hopes were shattered. But Simon Cowell brought them back, this time as a group. And though they only finished third, Cowell signed them to his label anyway.

Cowell’s instinct paid off. Not only could the boys sing, but their good looks, natural charm and an explosion of social media has had teenage girls screaming, crying and swooning across the globe. The band has 14 million followers on Twitter, 19 million on Facebook and more views on YouTube than the population of Great Britain.

Their new documentary "This is Us" debuted in New York Monday night. It’s a look at the band’s life, on and off the stage. The band insists the music matters most, but the heartthrob aspect of the band’s appeal is lost on no one, certainly not them.