The Birds of a Feather singer revealed to British Vogue that she and her brother know what the other person is thinking with just a look, a skill which comes in useful when they're writing music together.
"I mean it's the sibling thing, you know? We look at each other in silence and we both know we're thinking the same exact thing. It happens constantly, especially with other people around," she shared. "He can also read my mind when writing and creating together. He knows what I'm thinking and feeling before I even know it."
Billie, 23, and Finneas, 27, co-wrote all of the songs on the pop star's three albums, while Finneas also produced the music. He has been teaching his younger sibling how to produce her own tracks and is working on his own projects.
He has also taken a step back from touring with his sister and has had less of a presence on her current Hit Me Hard and Soft Tour, which begins its European leg later this month.
Elsewhere in the interview, Billie shared how Finneas and their parents help her feel better when her "tank is running low".
"I just love being around people that I love, people that make me laugh and make me feel whole. You know: kindred souls. That's the stuff that keeps me sane. Laughing really is my cure," she said. "Also, I feel like being with my brother is kind of my cure, and my mama and my dad. I feel like they are always the ones when it is getting too much. Really Finneas makes everything better."
