I want to sell out arenas and make an album and work with some of the best artists in the world.

I want to sell out arenas and sell millions of records.

It's just impossible to believe I've become good friends with some stars like Justin Bieber. I would call Justin a friend, someone I hang out with. It's really weird.

A personal highlight was probably when we got a No. 1 in the U.K. and when the album went to No. 1 in America. The top four that week was us, Adele, Guns N' Roses and Bruce Springsteen. It was ridiculous seeing those names there. Being the first band from the U.K. and Ireland to go to America and debut at No. 1 is just unbelievable.

I had my first kiss when I was 11, but I think I've blocked it out of my mind because it was so bad. I'm not even sure it counts as a kiss.

Katy Perry still gets me every time. She's very funny in person! We met at the Teen Choice Awards and she pulled my cheeks apart and told me how cute I was. My life was literally flashing before my eyes!