Running Man's Monday couple Song Ji Hyo and Gaeri had a fight.

On the episode of "Running Man" which aired on January 19, 2014, actresses Park Bo Young and Lee Sae Young, and actor Lee Jong Suk of the recently released film "Boiling Youth" made their appearances.

Park Bo Young, Lee Sae Young, and Lee Jong Suk transformed into high school students and raced across the farms.

On this day's episode, the Running Man members went to a street market and competed in couple teams. Song Ji Hyo and Lee Jong Suk had to partner up in order to succeed in the couple mission as a secret couple. Gaeri said referring to Song Ji Hyo said, "She is my insurance," and Song Ji Hyo, obviously hurt, picked Lee Jong Suk as her partner.

On the second game, Song Ji Hyo gave her had to Gaeri. Song Ji Hyo, asking, "Are you ticked off at me?" and picked Gaeri as the partner. Gaeri, as if he had forgotten about what had happened before with Lee Jong Suk, held Song Ji Hyo's hand, smiling widely.