I got my hands on the aphrodisiac drug that's been trending online, and without knowing how to use it properly, I decided to test it on my closest available subject—my stepsister. Soon after, I heard my sister's voice, which I'd never heard before, echoing down the hallway. When I peeked inside, I saw her frantically masturbating. That night, I heard faint moans again. Convinced of the drug's effect, I sneaked into her room. Under its influence, my stepsister began twitching and reacting intensely. That pure, adorable girl was now trembling and climaxing violently on my cock. With a trembling voice, she whispered, "Onii-chan... my body... feels so strange... please... give me your cock..."