Incestuous mother lusts after her son's masturbation tissue

One day, Ryoko was cleaning her sons' room. There, he discovers an obscene magazine and a tissue covered in sperm. Ryoko gets horny when she smells the scent for the first time in a long time, and she can't help but masturbate. She was so absorbed in her life that she didn't even notice that her second son, Natsuki, had come home. Natsuki has seen everything. In such an inexcusable situation, Ryoko confessed her lonely feelings to Natsuki. Then, Natsuki gently hugged Ryoko's shoulders...