His balls empty, finally. Billy slumped on his mother's naked body, gasping. Joan hugged his hips with her creamy thighs, caressing her hands up and down his back. She shivered with pleasure, surprised at what they had done. She was more surprised at herself than with Billy. He was young, feeling his sexuality bubbling hotly. She was his mother, and she felt she should have known better.

Yet, Joan had allowed her cunt to guide her thoughts, allowed her pussy to cause this. Part of it was, she knew, because of that pretty receptionist. She had allowed that to happen because her need had been so long denied, and she had allowed her son to fuck her because that gnawing need had been awakened by what happened in the doctor's office.

But Billy.

Why had he suddenly shown such an interest in her, his own mother? Joan didn't understand that. Looking up the girl's dress had started it, of course. But wouldn't her son have wanted to fuck that girl, instead of her, his mother? The truth of that, she realized, was that she, his mother, was available where the girl in the office had not been. She had undressed while he stood watching her, and the fact that she had not known it did not relieve her of guilt. She could have covered herself when she found out he was looking, but she hadn't.

All it took was for her son to say he wanted to fuck her, and she was on her back, legs open. It was a disgrace.

"Please, Billy," she whispered. "Get off me."

Billy pulled his cock free of her cunt, looking down at her. Feeling ashamed now, Joan tried to hide her nakedness from him.

"Go away, honey," she whispered. "Don't look at me, please."

Billy left her, and Joan began to sob, but she wasn't sure whether her crying was with delight, or guilt.