Obviously I love writing with Katy [Pery], I feel like we're the same person when we write together. Even though we fight a lot, we fight over every line and we pull each other's hair and we cat-fight all the time, it's always worth it in the end.

I was writing songs as a kid about leprechauns and Catwoman and teapots - whatever it is that little girls wanna sing about. The first song I wrote was called "Kitten." It was about a boy named Liam, who I was just crazy about.

In real life I'm pretty easy going and pretty chill, I'm not the party girl who will go wild and crazy necessarily.

Cheating is bad. That's a big mistake I've made, and I've really hurt people. I've never lied about it, though. I've always been honest.

Obviously I love writing with Katy [Pery], I feel like we're the same person when we write together. Even though we fight a lot, we fight over every line and we pull each other's hair and we cat-fight all the time, it's always worth it in the end.

I think I've learnt a lot about bullying and how to deal with bullying and how to get over that and to just be yourself and forget the haters.

When I go and write with other artists - a lot of the time it's with them - it's like a therapy session almost. I ask them what they're listening to and what they're going through and what their influences are and I try to get inside of their head and step into their shoes for a second.