Adachi no Naoko, incest, mother and child fertilization

His mother, Naoko, was a masturbation who could not be held by her husband. Isn't her son Kazuya having an affair when she sees such a mother? I was worried that such a thing would not be done, and today Kazuya offers to her mother, who is still working on masturbation, that she will never comfort herself. She was a mother who resisted, but she felt the affection of her son and had sex with him.