PFES-040 Spending seven days in secret adulterous sex with her slutty sister without her finding out. Fua★

One day, while living together with her, my girlfriend's older sister 'Fuua' came to stay at our place for seven days. This tall, long-limbed sister who was both cute and mature didn't look like her younger sister at all... Somehow, we ended up in a relationship where we accepted each other and entwined our bodies. As we felt guilty, our adulterous sex grew more intense. We hid it from my girlfriend, but gradually became bolder in indulging our pleasure over those seven days.