The younger brother in the movie was truly lucky to come to his older brother's house to visit at the same time his older brother was away on a business trip and only his sister-in-law was at home. It's true that fire burns like straw after a long time. The time without her husband by her side has made Suzuki unable to control her desires and sudden urges like any other married woman. This made her feel very uneasy and uncomfortable and had to find a way to escape. Of course, in a small house with just the two of them, her husband's sexual and provocative actions to help her achieve that desire are all too understandable.