After my father-in-law passed away, my mother-in-law, Miki, lived alone. Worried about Miki's lack of vitality, her daughter and husband decided to move in with her. Although their married life was happy, her son-in-law lived in constant torment. My mother-in-law's body was so alluring that I couldn't help but fantasize about having sex with her. One day, my son-in-law came home early. My wife had gone shopping. As my mother-in-law prepared to take a bath, my son-in-law grabbed her, caressed her, and said she was incredibly attractive. Although my stepmother was unwilling, Miki was inherently a lecher. Despite her protests, her vagina immediately responded, beginning to secrete fluids. "I can't believe... my daughter's husband has such a strong penis... I'm in trouble..." Miki unintentionally experienced multiple orgasms from her daughter's husband's penis. One day, as these days passed... finally, her daughter witnessed her and her son-in-law's affair...