"Oooo," Susan mewled as she saw Mary wrapping her lips about the man's cock. "She's going to suck him, Bobby!"

"You mean Mary is going to suck on his cock? I didn't know people did that, Mom."

"Oh, yes, baby," she cooed. "It's delicious for a girl, using her mouth that way, very delicious."

Mary obviously knew she was being observed, and was enjoying putting on the display of erotic activity before an audience.

Susan and her son saw the girl slide her lips slowly along the throbbing hardness of the man's cock. Mary paused, then pulled more prick into her mouth until, finally, her lips were surrounded by the thick patch of hair at the base of the cock. Susan hissed hotly, her excitement intense. Bobby was making gulping sounds, and his hips were thrusting his cock into his mother's fist faster. His finger inside her cunt was stabbing with short, jerking movements that caused his mother's ass to twist slowly in a grinding motion.

For a while, Mary bobbed her sweet face back and forth, her lips sucking on the man's cock. Finally she pulled her face away and raised her head until Susan and her son could see the ecstatic expression on her face as she licked her lips.

Then the man sprawled on his back, his cock standing straight up as though being offered to Susan. When Mary climbed on top of the man, Susan and her son could see the way she squirmed her blonde-haired cunt down onto his prick. As Mary began to thrust her hips up and down, they could see her cunt fucking that hard cock.

Without a word, Susan twisted to one side, thrusting her ass toward her son. She could still look down upon Mary's shapely, pumping ass, though. Bobby shoved his mother's dress to her waist, yanked her panties down and, leaning over the window to keep his eyes on that lovely ass three floors below, fucked his cock into his mother's cunt.