I was living in a school dormitory, but I came back to my parents' house during the long holiday. My parents and grandfather live in my parents' house. My grandmother passed away a year ago, and my grandfather was so shocked that he was bedridden, so my mother was taking care of him. Speaking of my father, he had no interest in his family and was always wandering around. One night, a strange voice came from my grandfather's room. Did a stray cat get in? That's the kind of voice it was. I was curious, so I opened the sliding screen. And then...in the room, my mother was sucking her breasts and lovingly stroking my grandfather's dick...