Jeong Woo is a husband who can't get an erection while his marriage is going down the drain. A friend and his wife from the States suggest a couples trip. Jeong Woo meets his friend's wife Hye Sook who is extremely sexy. His 'package' keeps getting stimulated every time he sees her. He tries to ignore it but every time he sees her, he gets sexual fantasies. Finally, he suggests to his friend, to 'switch' partners.