A son's affection for his mother gradually turned into sexual desire. One day, he approached her, and although she managed to reject him, his feelings would not subside. During a hot spring trip together, Yumi finally gives in, thinking, "Just this once..." As her son caresses her, she reaches climax from feeling a cock for the first time in years. She thought it would end with just one time... Yumi struggles between the joy of being seen as a woman and the pleasure of immoral desire. We present a forbidden incest story where they sought each other out, even though they knew it was wrong.
