Billie Eilish's brother Finneas has told how the siblings had the "longest, biggest argument" while writing Hit Me Hard and Soft.
The sibling duo wrote and produced Billie's latest album together which was released in May.
"I think the longest, biggest argument was during a period of transition in maybe both of our lives where we were just trying to be kind of honest," Finneas, 26, admitted on Hot Ones Versus.
"To give (Billie) credit, I was very much high and mighty about, like, 'You're not being honest or authentic enough.' So I learned a lot from being too egocentric in that process."
Billie, 22, spoke about how during the recording, Finneas would be "a lot of times barefoot, a lot of the times in very filthy shoes," adding,
"My face is right there. And actually we filmed so much in making the album that almost all the footage is his feet and then me."
During the interview, Finneas revealed What Was I Made For? which appeared in the Barbie movie, as his favourite song of Billie's.
"I love that song. That song's great. There's such a tender, heartbreaking thing about that song. I have such a fond memory of writing it. We got to like perform it for that whole year. And it got us into Barbie's entourage, which was such a fun entourage to be a part of, they were all such cool, nice people."