Ariana Grande headed straight back into the recording studio after hearing Nathan Sykes' vocals on their duet Almost Is Never Enough because she refused to be outdone by The Wanted star on her own single.
They recorded their parts separately for the track, but when Grande received the boyband member's verses for the song, she was so impressed, she felt it necessary to step up her efforts and improve on her own performance.
She tells Britain's Daily Star newspaper, "Our manager Scooter Braun emailed me and said, 'Check this out.' Nathan killed it. I had to go back in the studio and sing more because he came in and did these vocal gymnastics and took it through the roof. I was like, 'This is my album, boy.'
However, the 20 year old admits she is always her toughest critic when it comes to her work: "I tear myself to pieces and I am an extraordinarily tough critic. In fact, I'm probably the most self-deprecating really hard-on-myself-person you've ever met in your life. I want to make sure I'm proud of everything I'm putting out there."
Grande and Sykes only met after the track was complete and have since found chemistry in real life, going public with their budding romance last month (Sep13).