Harry Styles has strict Twitter rules

Harry Styles tweets as if his grandma is reading it.

The One Direction star has become a global sensation along with bandmates Zayn Malik, Liam Payne, Louis Tomlinson and Niall Horan.

All five boys have Twitter accounts with millions of followers, but stay careful about what they write as they know it could be seen by the wrong person.

"You just have to be aware and not share too much. Tweet as if your grandma is going to read it!" Harry advised British We Love Pop magazine.

Niall added: "That's it. I once heard: 'Don't tweet anything that you wouldn't stand on a chair and say to your mother.'"

Harry, 20, is generally seen as the ladies' man of the group and has been linked to stars including Taylor Swift and Cara Delevingne.

Niall has also had his fair share of attention and is recently believed to have ended a relationship with model Barbara Palvin.

The Irish funnyman could be on the way to stealing curly-haired Harry's crown.

"Niall is a secret ladies' man. He's just too cute so you don't see it coming. He gets about bless him," Liam laughed.

The band was formed on the 2010 edition of The X Factor UK and has been going strong ever since.

All of them maintain that they rarely argue, apart from when it comes to decisions such as what they want to have for lunch.

"They eat outside!" Niall joked about the losers of the lunchtime battle.

Harry added that it's only "trivial" things they fight about it.