She dropped her free hand and began to slide her hot, moist palm up and down her thigh. The dress moved along her flesh, creating a tingling sensation in her body. Still pumping his cock, she drew her hand up her body and curled her fingers about one straining tit, wishing her son would play with her tits. She dug her fingers into the springy tit mound and moaned softly, her eyes glazing in passion. Her hand beat faster on her son's cock, her excitement mounting now. Her blood seemed to be boiling in her veins, and her hips shook, jerking back and forth as though she, too, were being fucked. She pressed the heel of her hand against her cunt, feeling the pressure on her distended clit.

She began to imagine her son's cock thrusting into her cunt, fucking her hard and wildly. As the image intensified in her mind, so did the speed of her fist on Bobby's cock. Her son was groaning now, his hips moving. Susan held her fist still, but tight, and let him fuck into it. The ecstasy finally got to Bobby and he was no longer looking down at Mary, but standing up straight, his hands on the window sill and his head back, eyes closed, teeth clamped.

Susan looked at her son's face, that young face now contorted with raging desire. She pressed hard against her cunt with the heel of her hand and looked down at her fist, seeing his cock fucking it. The smooth cock head flashed back and forth, disappearing and reappearing quickly in her fist. She saw his glistening cock head, smeared with the dripping juices from his piss hole. The palm of her hand was wet and slippery with the juices, too, lubricating her tight fingers.