On working with Shawn Mendes on "Señorita": "I mean, I love him. We have always connected; we have the best time together. Shawn texted me the idea for the chorus for 'Señorita.' He was like, 'Hey, what if we work on this and do it together?' I was on the Taylor Swift tour and hadn't been in the studio for a while. I didn't want to do it, and then a few months later, I couldn't get the song out of my head. I [finally] told him, 'I think we should do this.' He was like, 'I don't want to do it anymore.' It went back and forth for, like, eight months. Then we finally went into the studio and reworked it so we both felt good about it, without any pressure. I love working with him so much."
On working with Ed Sheeran for her upcoming album: "It's probably one of the most surreal things that's ever happened. I actually cried the first time I met him, when I was about 16. I just love his music; he's been the soundtrack for my life. By the time we worked together for this album, we were already friends, so we were just talking about my life, and we wrote a song that really captured it. I felt very vulnerable, but that's what writing sessions are all about."