5 Seconds of Summer forget their lyrics when they spot a hot girl in the audience.

Michael Clifford, Luke Hemmings, Calum Hood and Ashton Irwin make up the Australian pop band, which has been taking over the world with catchy tracks such as She Looks So Perfect and Don't Stop.

They're becoming pros at live shows, thanks to supporting Brit boyband One Direction on their Take Me Home and Where We Are tours.

Next year 5 Seconds of Summer will kick off their own Rock Out with Your Socks Out Tour, but they're a bit worried pretty fans may put them off.

"We have definitely forgotten the lyrics before," guitarist and vocalist Michael admitted to British newspaper Metro.

"It's really embarrassing because you'll be singing the words and then you'll see [a hot girl].

"It's not like, 'Wow, I love you,' it's just 'Oh, she's really attractive.'"

Luke, Michael and Calum are 18, while Ashton is the oldest at 20. They're busy with their budding music careers right now, but it doesn't stop the boys thinking about love.

"I wouldn't mind a girlfriend," lead singer Luke smiled.

"But I don't think it would work; there's just not a lot of time."

The band's popularity seems to be showing no signs of slowing down. But Calum insists it won't change them.

"The whole fame aspect and stuff like that..." he mused.

"Ultimately, we're just a pop-rock band who play music. We're nothing special, we're just dudes, and I think that's the difference between us and other people."

The Rock Out with Your Socks Out Tour kicks off in May next year.