They'd been stooping, holding onto the window sill as they peeked, and Rod moved his feet back on the grass so as to make his pulsing prick more accessible. He knew that his lovely sister was really steaming, as she enjoyed watching their beautiful mother being fucked, but he didn't do anything to help her out. He wanted to keep on watching the exciting erotic scene, and he knew, anyway, that Betty wouldn't hesitate about telling him if she wanted to be fucked, sucked, or fingered right then and there.

Betty quickly got his stiff cock out into the open. She wrapped her fingers around the hot shaft and stroked her hand up and down a couple of times, sliding the loose sheath of skin over the core of hard meat. Then she pushed her hand down to the base of his cock, pulling the skin back and causing his purple cock knob to pop out. She licked the swollen glans a few times and then engulfed the big knob with her mouth.

Rod gritted his teeth and tightened his grip on the window sill as the wonderful sensations of his sister's hot mouth encompassing his throbbing cockhead sent his passion soaring even higher.

Watching his mother being fucked by the handsome Mr. Anderson while his sister sucked his own cock really turned Rod on. He began making little hunching movements, pushing his prick a little deeper into Betty's greedily sucking mouth each time, and she willingly accepted more and more of the stiff shaft.

Rod hadn't been cheated in the pecker department. He was only sixteen and he already had over seven inches. And right then his fifteen-year-old sister was taking just about all of the throbbing length of cock into her mouth and down her throat. He could feel her throat muscles working around the glans each time she pushed her face forward and buried her nose in his pubic hairs.