During a segment of the show, the cast played a game in which each member had to take on Song Ji Hyo in a round of rock, paper, scissors. If the actress came out on top, she would receive a chance to slap the opposing player on the forehand in which at the time, the person must maintain his or her initial facial expression - failed to do so would result in a loss.

Song Ji Hyo won her rounds and eventually came around to slap Kim Jong Kook. Once she did so, Kim Jong Kook could not hold in the reaction and dropped his head. Seeing this, Jeon So Min joked, "The sound he made wasn't of pain but him getting mad." 

Check out the funny clip above!