"bad guy (remix)" by Billie Eilish feat. Justin Bieber To be honest, Billie Eilish does "bad guy" all by herself on this insanely addictive track ("duh"), but the coolest part about this duet is the fact that Eilish has been a huge Justin Bieber fan for years, way before she was famous — so the fact that they collaborated together is sick beyond words (and super exciting for her).