Mark found himself following the strokes with his own hand on his cock, urging him on, urging him to go faster, to fuck her harder.

"Give it to her!" he whispered. "Fuck her! Fuck her! Fuck her! Fuck her!" It was a near silent cadence as he jerked off to the sight of Jody being skewered by his dad's big cock.

Jody suddenly cried out and began thrashing on the bed. He watched her cumming around his dad's cock, entranced at the sight. His dad continued to pound down into her, squashing her beneath him as he slammed into her again and again. Then he groaned and collapsed on top of her. He lay there unmoving for several seconds, then rolled off her, letting her unbend.

Mark stared at his sister's naked body as it lay almost spreadeagled on the bed. His father grabbed his underwear from the floor and pulled it on with his back to the door.

Mark dared not delay any more. He closed the door and sped down the hall to his room, closing the door just as he heard Jody's door opening. He listened to the sound of his father's footsteps going down the hall, then heard his door close. His face was flushed and he was sweating. The images he'd witnessed raced through his mind.

He wasn't, for some reason, shocked that his father would fuck Jody. Oh, he was surprised that his father had a sex life, as most children were. He'd never thought about his old man fucking anyone before, not even his mother, so that was kind of a weird thing to witness. He didn't hold it against him for fucking Jody though. He envied him, in fact, and tried to figure out how he could get in on it.

If Jody would fuck his dad, surely she would let him into her pants, too. Hell, he was a lot better looking than the old man. He might not be as well hung, but he could fill her little box okay.

Then his thoughts shifted to Keri. Was the old man fucking her, too? His cock pulsed at the idea.

"What the fuck are you doing?"