“Bad Boy” is a song by South Korean singer Chungha and Danish singer Christopher. It was released on September 23, 2020 by MNH Entertainment, Parlophone Denmark and Warner Music Korea.

The artists' first collaboration work was originally planned to showcase during Christopher’s concert in Korea this year, which was canceled due to the coronavirus pandemic.

Christopher, known for his love for Korea and K-pop, brought up the idea of working with a K-pop star for his concert.

MNH Entertainment said that Warner Music Korea offered Chungha the idea, and she gladly accepted it because she had been a fan of Christopher’s music.