NHDTB-371 Every night, I secretly played with my sleeping sister's anus until it became so loose that my dick could go in all the way to the base.

Day after day, night after night, my brother subjects me to anal sex. In the dead of night, as I sleep in my futon, he sneaks in and pulls down my pajamas, thoroughly playing with my defenseless ass! At first, even one finger was too tight, but as days passed, it became two fingers, three fingers... eventually even his dick!!! And then, without realizing it, my sister found out that her anus had been developed on its own…