Drunk, younger sister slept in the wrong room of her older brother...

My father remarried another woman, so suddenly I had a new mother and a younger sister. I felt nervous, worried, and tried to be a good older brother. But when I met my new younger sister, I was very disappointed. She seemed like a rebellious teenager, very unruly, selfish, and stubborn. I really don't know how to live with this person anymore. When she came home drunk, she accidentally entered the wrong room and ended up sleeping in the same bed with me.

I woke up suddenly and saw her face right next to me, my body reacted unintentionally to her cute face that she normally didn't show. Unable to resist, I touched her body all over, unintentionally waking her up. Although she said to stop, through her reaction, I knew she was also feeling extremely excited and pleasured. I went further and had sex with her. And from there, our twisted relationship began...