An incident that happened when I visited my friend's house. After coming back from the convenience store, I was waiting alone in the living room when his sister—known for her big tits—approached me with a cheerful "Long time no see?" I was happy she spoke to me, but her panties were showing and her breasts were so large that I couldn't keep my eyes steady. Then she said, "I want to see the massager," and picked up a vibrator. I simply checked if it was working properly due to a loose connection and handed it back, but she said, "This will relieve my shoulder tension," and placed it on her shoulder. Suddenly, she moved it to her crotch and started moaning loudly. The atmosphere instantly grew tense as the bond between us deepened further.