Imprisonment of Sister Teachers

The two sisters live in the same house and are teachers at the same school. Two years ago, my sister brought her husband into their home, and since then, she, her brother-in-law, and her younger sister have lived together. A year ago, my sister was raped by the student's parents during a home visit, and she has since become sexually frigid. She took advantage of the situation and had sex with her brother-in-law. Although my sister was aware of it, she never dared to expose it. Later, a delinquent student discovered the secret between the sister and her brother-in-law during a home visit. The delinquent student took advantage of this secret and the jealousy between the sisters to take possession of both sisters.