I've been living with my sister, my husband (who is also my brother-in-law) who lost his job, and my brother-in-law for three months now. The younger brother would pay his older sister a small token amount of money for doing housework for him. The younger brother feels a strange sensation in his groin as he watches his older sister comforting his depressed brother-in-law. The older sister, while removing the comforter to clean her younger brother's room, notices his erect penis and feels something is amiss. One day, while we were drinking together, I discovered that my younger brother had been paying a considerable amount of money to prostitutes. "What?! You're paying that much? What a waste! Give me that money instead, hahaha." The younger brother was confused by his sister's words, but when he went along with it and brought up the topic of negotiation, she replied, "Huh? If you're going to pay me, then it's fine, lol?" Fueled by alcohol, the brother and sister start a compatibility test in a strange mood, and they both begin to get excited, finding themselves in a situation they can't stop... While both try to keep things casual, the sister and brother cross the line and things escalate further and further...