"Gu Family Book" Sung Joon hesitates when he sees Bae Suzy without her shirt.

April 22, the 5th episode of the MBC drama "Gu Family Book" featured Gon (Sung Joon) getting butterflies in his stomach after seeing Dam Yeo Wool (Bae Suzy) treating her wounds without her shirt on.

In this episode, Jo Kwan Woong's (Lee Sung Jae) men attack Park Moo Sol's (Uhm Hyo Sup) residence. Dam Yeo Wool and Choi Kang Chi (Lee Seung Gi) fight them together. Both get minor injuries from the sword fight.

Gon sees Dam Yeo Wool's injury and asks, "Why are you hurt? Who did this?" When Dam Yeo Wool asks him to deliver medicine for Choi Kang Chi who received more injuries, Gon becomes extremely jealous. Even though she had asked him to tell him "Thank you" for saving her life, Gon tells Choi Kang Chi, he only says "This is medicine from Dam Yeo Wool" and gets into a verbal argument with him.

Gon goes to Dam Yeo Wool's room to report to her that he had delivered the medicine. When he enters however, Dam Yeo Wool is not wearing a shirt since she is treating her wound on her shoulder. Gon hesitates at the sight and finds himself unable to answer her questions from being nervous.

When Gon leaves her room, he looks back at the door of Dam Yeo Wool's room with a deep look in his eyes.