Ariana Grande's collaboration with Iggy Azalea on 'Problem' seems like a no-brainer now that the song has become one of the biggest tracks of 2014.

But Azalea has revealed that the collaboration almost never happened, because she initially thought her own material was "too risqué" for Ariana's style!

In an interview with The Grammys (quotes via MTV UK), Azalea said that she turned down an opportunity to appear in Grande's first album, 'Yours Truly.'

"She reached out to me for her first album and I didn't do it even though I thought she was amazing, because I thought she was much younger than what she is," Azalea explained. "When I realized she was so close to my age, I was like, 'Wait you're an adult!'"

"I felt that my music was kind of so risqué and I knew she had a Disney show. I didn't feel like it was appropriate but then I actually met her and I found out that she's a grown-up and I was like 'Oh ,OK!'"

(Grande appeared on Nickelodeon's 'Sam & Cat,' not a Disney show.)

We're glad that she changed her mind, because we can't imagine 'Problem' now without her!