A married woman named Chinamin lives together with her beloved husband and his father-in-law. However, one afternoon... she gets caught masturbating by her father-in-law, leading to him forcing himself onto her. Unlike her indifferent and clumsy husband, this experienced man knows how to please her both roughly and skillfully. As they indulge in passionate sex, the wife finds herself being repeatedly penetrated and filled with pleasure. Eventually, the once virtuous housewife becomes so consumed by lust that there's no going back to her innocent days...