One day, while visiting a friend's house, his older sister began seducing me by exposing her breasts. When she found out I had peeked at her while she was bathing, she provocatively asked, "Will you wash my body?" Pretending to wash her, I started touching her, and she responded sensitively, clearly aroused by the erotic atmosphere. Unable to hold back any longer, I ended up penetrating her right there in the bathtub. At that moment, our relationship changed completely, and I could tell this wouldn't be the last time.