Sayako lives with her husband and son. Sayako and her husband are still close, often getting intimate when their son isn't looking. However, recently her husband's penis has become soft, making it feel good but not fully satisfying. Sayako has been secretly masturbating to release tension. One day, she was caught by her son who said, 'Dad's dick can't satisfy you, right? Let me put mine in.' From that day on, Sayako started having sex with her son when her husband wasn't looking...
