Mirei, my older sister, is neat and clean even from my younger brother's point of view.Her older sister secretly brought back a man, so she wanted to see what kind of man she was and pretended that she wasn't there.I couldn't believe my ears.Surprisingly, the man was her sister's master!The sound of body and bodily fluids colliding and the obscene voice stimulate my crotch.And I peeked at my sister, who became a M slave, indulging in muddy sex with a middle-aged man.However, her peeping was found out and her sister stopped her.