Watch Bebe Rexha Say Louis Tomlinson is Like a Brother at iHeartRadio Festival

When artists get together for a collaboration, it can feel very business-like and most of the time, they don't even need to be in the same room. But, this wasn't the case for Bebe Rexha and Louis Tomlinson when they recorded their single "Back to You."

Backstage at this year's iHeartRadio Festival, Rexha told Billboard how Tomlinson first sent her the song and how their first interaction led to their now sibling-like relationship.

"The second I met him, he was kind to me and my team," Rexha recalls. "He's just cool. I don't feel nervous around him -- he's like a friend now, and it's cool to work with friends."

The singer also discussed working with country act Florida Georgia Line and how that changed her view on country music. 

"I think it changed my mind about music in general," she says about "All Your Fault." "I'm learning that music business is based off of just great songs."

Watch Bebe Rexha talk about more collaborations and new music on the horizon in the video above.