Ariana and myself have known each other since we were teenagers, but Thank U, Next was only our second time working together. I had done My Everything [the title track from Grande’s second album] but otherwise we hadn’t worked together for years.

It all started out because I was a fan of a play called 13 she was in, and she was a fan of a movie I was in called Hairspray. We ended up filming across from each other ...