Sophie could feel her son's eyes on her ass as she ascended the staircase one step at a time. Meanwhile, she was thinking frantically.
Yes, she was thinking about the fact that she had just offered her lonely son her ass. As a horny, guilt-ridden Catholic teens, she and her friends had decided that it doesn't count when it's anal. She could comfort him that way without it really being incest.
And yes, she was thinking about how she had just given her own son a blowjob. She hadn't even really been thinking when she did it. She touched his hard cock (hard from the thought of fucking his own mother in the butt apparently) and then her hands just automatically opened his belt, unbuttoned his pants, and reached inside.
Then, again without thinking, she had bent her head down and put her boy's rock hard, big beautiful dick in her mouth.
Actually, what was really on her mind as she slowly walked up those steps, was just how big that penis was. It's wasn't SO huge. It wasn't the biggest she had ever seen. It wasn't even the biggest she had ever fucked.
Her son's penis was just bigger than any she had ever taken in her ass.
In fact, she had made a rule a long time ago that she would never a cock more than 7" (18 centimeters) long in that particular hole. His dick was definitely bigger than 7 inches.
And yet, she had promised her son he could put it in her big round butt. She had promised herself he couldn't put it in her pussy. That would clearly, completely, be incest. It would be wrong.
So that's what she was really thinking about by the time she reached her bedroom door and started to slowly turn her doorknob. Billy moved right up behind her. She could feel his cock very clearly against her bathrobe covered rear. He had stepped out of his jeans and left them down in the living room. He was only wearing a t-shirt and flimsy boxers now.
He moved one hand around her waist and pulled her closer to his body, harder against his cock. She felt his breath right against her neck and ear, which caused her to suddenly take in her own breath. She could feel him smile in reaction to this, as he nestled his face into her sensitive neck.
Sophie had always loved to be kissed there. Right where her shoulder meets her neck. It drove her crazy. She threw her head back and sighed in surrender.
She realized she had been holding tightly on to the doorknob, white knuckles showing. Now she pushed it forward. Billy pushed her forward, not with his arms but with his whole body. They moved as one hot mass of flesh toward her queen size bed. Right about now she felt like a queen, a queen who could have anything, anyone she wanted, even her own son.
"But only in the ass," she reminded herself.
"I know Mom, only her your butt" he said in her ear, making Sophie realize she had actually said that out loud.
She also realized that they were now on her bed; she with her face down, he on top of her. Billy was running his hands along the outside of his mother's thighs. Then he was fondling her hair, her ear, neck, chin. Then he had his fingers in her mouth and she was sucking on them.
"Just like he used to suck on my nipples," she thought to herself. And the thought made her nipples harden even more.
"Just like I used to suck on your nipples, huh, Mom?" he whispered in her ear.. It sent a shiver down her spine to hear him echo her thoughts. She definitely hadn't said it out loud this time because his fingers were in her mouth.
Maybe they were just on the same wavelength. Maybe she hadn't actually said that last thing out loud either?
Now his hands had moved down to the hem of her robe. Now they moved up her legs. He ran his hands over her smooth ass. He moved them down her curves, between her cheeks. Her son's finger's grazed against her tight back entrance. Then her son was touching her pussy.
The feeling of his fingers in that forbidden place suddenly startled her to attention.
"No, Billy. No. You can't touch me there. Only my ass. That's the rule." she said, surprising herself at how sober she suddenly sounded.
"But you touched my penis?" he said in a soft, half matter of fact, half pleading voice.
"That was different. You just can't touch me there." she said, matter-of-factly.
"Okay." he said, trying not to sound too disappointed.
Then Billy remembered what he had been thinking about while his mother seemed to take an eternity to climb the stairs. He slithered his body down, across her back, until his face was directly in line with her soft, round cheeks. His eyes could just barely see under her robe from the angle her was looking and the way it had been ruffled around from all the movement.
Now he decidedly grabbed each side of the bottom of the bathrobe and FLIPPED it up.
There. There was a perfect view of his mom's bare ass.
He buried his face in it.
"Oh, Billy.... oh, sweetie... ohhhhh...." Sophie sighed over and over. Billy's nose was in the crack of her butt and his tongue... his tongue was licking her ass hole and she was loving it.
"I guess I got my answer: ass licking doesn't count." Billy thought to himself. "I also wonder if licking her pussy counts but given how she reacted to my fingers, I probably shouldn't try."
Instead, he moved his hands over her ass around to her hips. He grabbed them and pulled so that his face got buried even deeper into her smooth cheeks. His tongue probed deeper trying to go INTO her ass, not just along the tight folds of her sphincter.
