PIP/Shunned/Noah the fall guy

I wanted Noah and Leah screwing each other, but I also wanted my mother to be fully aware of the fact they were doing it. Actually, I even wanted her encouraging it. But first, the entire idea was so hot that I had to push my mother down to her hands-and-knees for a moment so I could buck my hips into her. This forced Noah and Leah to be pretty much pressed against the walls of the tub. It was pretty clear there was going to be very little space for this. I had a pretty good idea of what I wanted though. I had Leah drape her body over the edge of the tub with her butt up in the air, and then I lined Noah up behind her. I took his tiny little pencil dick and lined it up with her entrance. For the final touches, I grabbed mom's hand and placed it on Noah's butt, and then I pushed her hand from behind. With this, despite them being shoved up into a tiny corner of the bathtub, I had Noah fucking Leah while I was fucking mom.

Mom continued to push Noah's hips in a rhythmic motion, making him have sex with his little sister, and here I had a beautiful side-profile of the entire hot scene of pre-teen on toddler sex. My mother, meanwhile, was letting out some low moans as I kept screwing her from behind. Except for that, they were all silent for a little while, but eventually Noah seemed to be the first one to notice something had changed. "Mmmm... mommy? What are you doing?" He asked her.

"What!?" She responded in confusion. "I, uhh... well, since you two already had sex, I wanted to make sure you were doing it the right way." She said.

"This huuurts!!!" Leah protested and then started shoving back, trying to escape from her position.

"The faucet's in the way!" Noah joins in with the objections.

"We didn't do it like thiiiis!" Leah kept on with it.

"Ok, ok. How about we all get out of the bathtub and set this up right?" She says as Noah and Leah break apart. However, after that, nobody is moving. I realize it's because I'm still holding my mother's hips in order to screw her. The moment I let go with my hands and slide my dick out of her she stands up and steps out of the tub and towels herself off. She then helps Leah dry off a bit, only her feet and ankles had been wet to any significant degree since she hadn't even sat down in the tub since getting in, and then she got Noah out and helped towel off his whole body.

"Alright, Leah, lay down on the bath mat." She instructed the 4 year old toddler, who unquestioningly did as she was told. "Now, Noah, get down between her legs. Put your knees here, and here. She instructed Noah, pointing to two spots between Leah's spread legs, close to her butt as her puffy little pussy was on full display. I was amazed to see this all unfolding. Once I'd gotten them started, they were moving on their own, and I was very interested to see what mom was having them do. Once Noah was in position, mom grabbed Leah by the knees and dragged her hips up onto Noah's kneeling thighs. She grabbed his penis and lined it up. "Alright, now all you have to do is push forward." She told him.

Noah did as he was told and I got to see my little brother's penis disappearing inside my toddler sister's tiny little pussy. The sight was so freaking hot I started cranking my shaft as I watched. There was something so wrong about the sight. It was far better than having my dick stuck up inside my mother. I just couldn't help imagining I was Noah and it was my dick up inside my little sister just like I'd been inside Hannah not too long ago.

WIP (I consider this about half-way through. More to come. Just not up for a long post right now.)