"Which do you like more, your older sister or me?" I promised to marry her and we would visit each other's rooms. I thought those happy days would last forever... until that day. As soon as she left the house for a business trip, my younger sister actively tempted me. Despite feeling guilty, I ended up having intense, endless sex with my younger sister, who was more erotic and cute than her. The days filled with sex with my younger sister were the most lewd and exciting in my life, during the three days she was away.