Mom was fucked right in front of him, and the son, as soon as he got an erection, would come close to her and commit incest as punishment! SHE-278

What are you saying over there, "Even if Mom's being fucked right in front of you, you won't get excited"? Well, let your mom go into the small room and see if she can resist being fucked so hard! If you only see the other person as your mother, you won't get an erection and want to fuck, right...?