Watch Three Families Under the Same Roof 3 for Free: How to Stream the Movie Online at 123Movies. . Three men and three women live in one house and live like a family. They share each other's lives, such as girlfriends, affairs, rent, and live while enjoying their own private lives. One day, when Ye-ri enters the house, a strange energy begins to circulate in the house. Meanwhile, Yeri begins to seduce Nam-soon, who is worried about her.