There was a part in the choreography where Shindong had to squat down. Sungmin knew that Shindong was feeling some discomfort on his kneecaps. As Shindong was about to get into the squat position, Sungmin quickly extended his hand, giving support to his kneecap. It was only a small gesture but it showed how warm-hearted Sungmin is.
[c. 陳干軒ganhsuan ,v.scarkyu]