During a torrential downpour, my girlfriend’s older sister Mitsuki arrives at our home drenched and teasingly asks why we do not have sex every day. With my girlfriend away, the sight of her sheer wet clothes, H-cup breasts, and seductive smile destroys my self-control. We plunge into forbidden sex again and again: she rides me hard on the sofa, wraps her soft breasts around my cock in the bath, and lets me pound her on the bed while her tits bounce. Even after morning comes, we keep fucking through the full 24 hours until it feels as though I have emptied a lifetime’s worth of cum.