My father remarried, and my stepmother, who never wears underwear, shows her huge asshole, making me go berserk and having anal sex. (Mei YD-717)

It's all the stepmother's fault for exposing her asshole while doing housework! The stepmother who came after my father's remarriage had an unbearably huge buttocks, so I grabbed her buttocks and penetrated her from behind, ejaculating inside her like that!