The younger brother in the movie was indeed very lucky when he came to visit his sister-in-law at the exact time when his brother was away on a business trip, leaving only the sister-in-law at home. It's true that the fire near the hay will eventually burn it. The time without her husband by her side made Suzuki unable to control her desires, sudden arousal like any other married woman. This made her feel very restless, uncomfortable, and she had to find a way to escape. Of course, in the small house with only two people, the provocative and seductive actions towards her husband's younger brother to help her achieve her desires are quite understandable.