One day, my wife's younger sister suddenly came to stay at my house. She seemed like a cheerful and kind schoolgirl, always smiling, but in reality, she had a completely different side. It turned out she harbored resentment toward me—she spat in my face and hurled cold, cruel words. I was shaken, unable to hide my reaction, and before I knew it, my penis was fully erect. Was I really a masochist? Realizing this, she began tormenting me relentlessly, forcing me to ejaculate over and over again.