Kim Chung Ha and Christopher's collaboration single has finally been released!

On September 28 KST, the two singers unveiled their new song "Bad Boy," as well as its accompanying music video. The single is a midtempo pop track based around light percussion and a calming guitar chords. The lyrics confronts 'bad boy'-loving girls, with Kim Chung Ha singing from the perspective of a girlfriend who thinks her boyfriend is not 'bad' enough, while Christopher sings from the perspective of the boyfriend, who has only ever wanted to be 'good' to her.

Meanwhile, Christopher first became popular in South Korea thanks to his 2019 single "Bad," which has been covered by a number of K-Pop idols, including B.O.Y's Kim Kook Heon and JBJ95's Takada Kenta.

Check out the music video above!