My sister, who was a very serious and kind girl, failed her entrance exams and enrolled in a slutty girls' school, and became a super slutty gal! Of course, all of my sister's friends are gals and sluts, so when they come to hang out in my room with my sister, they unexpectedly invite me to do something sexy from the top of the bunk bed! They flash their panties from above, making me get hard! Of course, they get me hard, and I get attacked and eaten up! And not only are my gal friends attacking me, but my sister too...