Living in my school dorm, I returned home for a long holiday break. My family consisted of just my parents and my grandfather. My grandmother had passed away a year earlier, and my mother had been taking care of my grandfather ever since, as he fell into poor health from the grief. My father, disinterested in family matters, was always disappearing somewhere. One night, I heard eerie noises coming from my grandfather's room—sounds like a stray cat sneaking in and doing something suspicious. Curious and unable to ignore it, I quietly slid the shoji door open. Inside, I saw my mother, her breasts being sucked by my grandfather, while she lovingly stroked his cock. The scene was vulgar, something I could never tell anyone, yet it struck me with an intense, overwhelming shock.