Forbidden humiliation ~I am my son's meat slave~

Sayoko, whose husband Ichiro won the election, became the wife of a lawmaker and is at the peak of happiness. The only thing I'm worried about is my son Yoshio, who is a NEET. One day, Yoshio came home and witnessed a lewd act between his mother and a stranger. From this day on, Yoshio's distorted desires target Sayoko, his biological mother... Yoshio, who has grasped a certain weakness, begins to train his biological mother as his sexual slave. What is the fate of the sinful mother and child? ?