The girl I've been dating for half a year isn't particularly into sex and is the studious type. Her sister, who is completely opposite in personality and somewhat airheaded, suddenly goes at me whenever we're alone… Her vivid, erotic body whispers seductively in my ear, boldly tempting me even with her sister by my side. Over three days, we had sweaty sex, gushing fluids, our bodies entwined and soaked. I'm already hooked on her sister—
