Stay and watch

Mark felt himself get hot as he watched Robin and had to bite his bottom lip from making a sound himself. Robin was now seated on the ground, she had one hand down her shorts while the up her top. Her eyes were closed so she couldn't see that her son was watching her. Not that she would notice it currently. "Oh fuck... "she moaned as she felt herself up. She pulled her hand from her shorts, her fingers were slick with her juices. Robin moaned loudly as she sucked her fingers. "Oh fuck me..." she muttered before pushing her hands back down her shorts.

Mark thought, "STOP!"

Things went silent once more and he walked back into the room. He looked down at his mother seated with a hand down her shorts while the other up her top. Her eyes were closed while a grin was on her lips. He found her extremely hot at that moment and he even forgot that he had twenty year old just downstairs dressed in a revealing teddy.

He picked up Robin and carried her down the hall to her room, the house's master bedroom. He placed her in the bed and laid her out before stripping her completely naked, sneakers and all. He pulled her hair out of the ponytail even. Mark stripped down naked himself and climbed on the bed. He was fully erect as he laid over Robin and pushed his manhood into her wet pussy.

Mark went at Robin a few times and orgasmed a few times as well. He only stopped when he was sore. When he climbed off his parent's bed, he was slick with sweat. Robin's snatch was open wide from his cock being pushed in and out for such a long period. She was still on her back, with her legs parted wide almost into splits while her hands were behind her head.

Looking around the room Mark decided to slip into the walk-in closet. It had a great view of the bed. He closed the door a crack and peered through before he thought "START!"

Robin lets out a scream, her eyes were wide. She clutches her sheets as her back arches on the bed as if she was possesed. "What the fuck!" she shouts her back still arched to the point where Mark thought she would snap in half.

Ashley suddenly burst into the room, Nick following close behind. "Mom are you..." she starts say until she realizes she looking at her mother naked, her pussy wet and dripping on to the bed.

"holy shit!" Nick remarks wide eyed.

"Sorry!" Ashley blurts as she started to push Nick out of the room.

Robin had not even noticed and was now just moaning and playing with herself panting.

As Ashley shoves Nick from the room her bare feet shuffle over Mark's discarded clothing. She looks down as she gets Nick out in the hallway. "Why are Mark's clothes here..." she wonders and she peeks back in the room with eyes narrowed. Her gaze slips to the closet and she thinks she sees someone.

Mark locks eyes with sister but he is sure she can't see him its too dark. He waits for a beat. His mother still moaning loud in the background but he and Ashley are in stare down of sorts. Finally Ashley back out the room closing the door after her. Mark could hair faintly on the other side.

"Get down stairs!" she orders Nick before shouting "Mark!"

The way her voice sounded even from behind the door he knew she was headed towards his room.

"STOP!" he thought.