Billie Eilish's entire family helped her write final line for Rosalia collaboration

Billie Eilish turned to her nearest and dearest to come up with the final line in her Rosalia collaboration Lo Vas A Olvidar (You Will Forget Her).

The Bad Guy star frequently collaborates with her brother Finneas O'Connell on her songs, but this time around, the siblings recruited the rest of the family for help with the closing lyrics.

Speaking to Zane Lowe on Apple Music, Billie explained: "So my Mom, my Dad, Finneas, me, Finneas' girlfriend Claudia, we all came down to the studio, and we listened, and me and Finneas were like, 'Should we just write this line right now?'

"So I was sitting in the room with my entire family. We both, all of us, including my dad and my mom, they were like, 'What if it was like....' We were all giving ideas. So technically they should have a writing credit, because we all wrote that line right at the end."

Their collaborative work saw Billie coming up with the final line of the song: "You say it to me like it's something I have any choice in / If I wasn't important, then why would you waste all your poison?"

Lo Vas A Olvidar is set to feature in the upcoming special episode of Zendaya's hit TV series Euphoria, which premieres this weekend.