Sumire-chan, my ex-live-in boyfriend and I broke up, and she suddenly came back to her parents' house. She's spoiled and selfish, but she's still got that charm. Seeing her like that, I felt a pang of nostalgia. When I went to call her from the old room she used to use, I found her masturbating, playing with her own nipples. I'd never heard her moan like that before. My cock got hard. I got caught peeking... From that day on, I became her nipple-obsessed sister's sex helper, and I was addicted to the incestuous summer days where I got to fuck her.