The husband went on a business trip alone, and the mother, Maiko, lives with her daughter's family because they were worried about her living alone. Although everything seemed fine on the surface, she was frustrated with sexual desire and indulged in self-pleasure every night. Then she found out that her son-in-law, Hikaru, had been secretly peeping at her lewd acts… When Maiko learned that he had a big dick, she couldn't hold back her overflowing lust and obscenely tempted him whenever she could. The son-in-law's giant cock swelled up every time he saw his mother-in-law's repeated lewd behavior, and finally, he couldn't take it anymore…
