The popular series "Creampie Incest" tells the tale of a beautiful mature wife who gives herself over to an affair with her father-in-law. After retiring from his job as a hard-working corporate warrior, the father-in-law is enjoying a carefree life, eagerly awaiting the birth of his grandchild. However, after learning that his son has erectile dysfunction, his attitude towards his daughter-in-law, Ayumi, begins to change, and one day... The father-in-law, who lives with his son and his wife, notices that his daughter-in-law, Satomi, has been acting strange lately. It seems that her libido has suddenly increased to an abnormal level since the birth of their grandchild. However, he is indifferent to his father-in-law, who does not see him as a man...