My sister, who is on her period, was in a bad mood as soon as she got home, probably because something bad happened outside. She's usually kind, but today she started to take it out on me and pick fights with me. She even made fun of my lack of feminine charm, which was one of my worries, and suddenly started stroking my dick vigorously, spitting on it, and licking it. Even though I was scared, my dick got hard in an instant... In the end, she squeezed out every last drop of semen from my tank until it was empty. Women are scary...