I think when you're writing songs, it's impossible to not draw on personal experiences, whether it be traveling or girls, or anything.

I wouldn't say I'm girl-crazy, because that makes me sound like a bit of a womanizer. That isn't really me. But I am quite flirty - maybe too flirty. I'm an 18-year-old boy, and I like to have fun!

I heard some stuff recently from Julian Casablancas, and his solo stuff is amazing. If I could write with anyone, it would be him.

And you still have to sqeeze into your jeans, but you're perfect to me.

You get moments all the time that kind of make you pinch yourself, some of them make you quite emotional. Winning a BRIT was a big moment because we were just so excited to be at the awards in the first place. Selling out Madison Square Garden was pretty amazing too. Then we woke to the news that our UK tour was sold out. It was crazy.

Some of them are funny. Some of them are ridiculous. Some of them are annoying. I don't want to be one of those people that complains about the rumours. I never like it when a celebrity goes on Twitter and says, "This isn't true!" It is what it is, I tend not to do that.

Age is just a number, maturity is a choice.