The moment Tatsuya came across his mother, Ayumi, doing exercises using a balance ball, he gasped. Her defenseless body curved along the curve of the ball. A single trickle of sweat oozed from there and trickled down her soft skin. The alluring scent of his mother's lustrous bodily fluids was so lewd that it shook Tatsuya's reason violently. This can't be allowed... Tatsuya pretended to be calm and tried desperately to control himself. But Ayumi, never dreaming that her daughter had such feelings, asked her to assist with the exercises...