My older sister, always wearing sleeveless underwear that exposed her breasts, let me see them completely unguarded. I was unconsciously drawn to her allure, and when she noticed my erection, I completely succumbed to her temptations. I learned a secret I wouldn't tell my girlfriend, and from then on, I began secretly being seduced by my sister while hiding behind her. (Shishido Riho DOCZ-003)

Her sister always wore a sleeveless bra, her breasts completely exposed. Looking at her exposed breasts, I couldn't help but stare, even knowing I shouldn't. She always caught me looking, and this time was no exception. While resting in the living room, I ran into her sister. Her sister's breasts were still completely exposed. I looked at her breasts, and her sister looked at me too. "What are you looking at?" I was nervous. I could only say I was just looking at her. Her sister said, "You're getting an erection, aren't you?" I was so embarrassed. Her sister had seen through me. I didn't want to tell my girlfriend this secret. From that day on, I began hiding behind my girlfriend, secretly being seduced by her sister. Whether I was sleeping or in the bathroom, whenever she wanted, I would be seduced by her. Her tongue would entwine around me, making me lose all thought. Her beautiful buttocks would bounce in the air, shattering my reason. Her sister even wouldn't let me ejaculate without a condom… Ah! Forget it! That's it!