My stepfather's wife is teasing me about my stepfather. Please forgive me now...

Momoko is a wife who has been married for three years and lives a happy life with her husband Keita, five years younger than her. One day, his stepfather, Tadanori, who was living in retirement, suddenly came without any contact. Tadanori, who had been keeping an eye on Momoko for a while, began to trot Momoko after seeing Keita fall in love with him. Tadanori begins to grope Momoko, who is not easily able to have children, while calling it a "infertility treatment." Even though she knows it's a bad idea, Momoko's sensitive body reacts twitching...