The idol star revealed that girl group members tend to put makeup even on their legs when going on stage. It's claimed that it looks prettier when your knees give off a light pink tone.

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Kim Se Jung then shared the secret to the perfect knee look. She explained that you put concealer on first then a pink blusher topped by pink body balm. 

The knee makeup was also previously introduced in 2014 as former f(x) member Sulli's stage makeup.

Learn the secret to idols' knee makeup from Kim Se Jung in the clip above!