Image copyright Getty Images Image caption BTS posed with Khalid at this year's Billboard Music Awards

When we ask Khalid about his collaboration with BTS, he gives us a cheeky smile.

"I have a strong feeling there will be progress... and something will arrive," he smiles.

Not elaborating too much, he says he tries "not to talk about" the South Korean superstars insisting he "doesn't want to cramp their style".

Photos from this year's Billboard Music Awards and an Instagram post show the guys know each other well.

At 21, Khalid has already collaborated with more stars than most of his peers.

He's worked with (among others) Imagine Dragons, Swae Lee, Martin Garrix, Pink, Marshmello, Shawn Mendes, Calvin Harris and Billie Eilish, someone who's become a close friend.

"She goes out there and inspires so many people. A lot of her fans have Billie inside their heart."

At Radio 1's Big Weekend in Middlesbrough, Khalid brought the singer out for a live performance of their duet Lovely.

He says that Billie is "so authentically herself" and is "undeniably Billie".

Image copyright Getty Images Image caption Khalid and Billie Eilish performing Lovely back in 2018 at the Governors Ball Music Festival in New York

"I see a little bit of the same thing that happened with me. They go crazy for her songs like they did for me and Location. You have Bad Guy and they all mosh. She also has her family with her and that keeps her grounded."

As well as the collaborations, Khalid has won Billboard Music, MTV and Teen Choice Awards.

His second album, Free Spirit, debuted at number one in America. Khalid tells Radio 1 Newsbeat he was nervous before it was released.

Image copyright Getty Images Image caption Khalid was promoted to the main stage of Radio 1's Big Weekend in Middlesbrough

"You have your whole life to write your first album. You don't have your whole life for your second one. But it makes me excited for the third, fourth and fifth albums. The music never stays the same."

The singer is also well known for his eclectic music taste, having previously shared his love for Fleetwood Mac and Sir Elton John.

Maybe more surprising is his love of Fireflies - the former number one by Adam Young AKA Owl City. The song topped the charts in both the UK and the USA.

"That song takes me back to my middle school year. I was in my feelings and wanted to cry.

"If you don't think Fireflies is a good song, then you're trying to be too cool for school."

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