“What’s funny about it is I actually thought it would flop…because the chorus doesn’t have a hook-at least what we wrote as the chorus,” Billie told Billboard. And trust, she had no idea this was coming. Even if you’re not an expert on all things Billie Eilish (which you should be, just saying), there is no way in hell you haven’t heard “Bad Guy.” Billie wrote the song with her brother, Finneas, and it surpassed “ Old Town Road” on the Billboard Hot 100-which is a big f*cking deal, considering Lil Nas X owned the charts for months.