I came over to my girlfriend's place today. The three of us—me, my girlfriend (a college student), and her older sister (an office lady)—started drinking at her place, hanging out in the living room since early afternoon. After a while, my girlfriend got drunk and collapsed on the sofa. With no choice, I relaxed beside her sleeping form when suddenly, across the room in the dining area, her older sister began stripping naked. Frozen in shock, I could only watch as she tied herself up with a hemp rope and started masturbating like a true masochist. Then she began speaking to me—words that seemed to beg for domination, pleading for me to train her. The scene was utterly shocking. Her intense eagerness, combined with my own weakening resistance to her seduction, leads into an intensely thrilling development.