This story is fictional based on simple facts. It contains incest, if this disturbs you, please do not read. I do not condone incest in real life, but I use this subject matter for adult entertainment only. This is a stand alone story, but reading previous chapters will help you with character details and development. This is a very short story with not much of a plot.
One afternoon when Zack came home from school, he heard some unusual noises coming from his mom's bedroom. For one thing, he didn't expect her to be home from work yet and the noises were sexual in nature. He didn't want to shock his mom, so he quietly approached the door to his mom's room.
When he snuck up to the door and peeked in, he saw something that he couldn't believe and his jaw hit the floor. He almost gasped but held it back as not to draw any attention to himself.
He saw his grandfather, Zoe's father, Theo, fucking his mom on the bed. Zoe was on her back with Theo standing at the edge of the bed holding her ankles with Zoe's legs lifted and spread wide open. Theo was plowing into Zoe with speed and force causing Zoe to groan every time Theo thrusted forward.
A brief description of Theo. He was Black guy, 5'9" tall, lean and muscular, probably weighed 190 lbs., and had a huge cock. His cock was at least 10" long and 3" in diameter, really thick looking, as big veins ran up and down it.
Zack stood there in amazement as he saw his mom getting fucked hard by his grandfather. It excited him to think that maybe he could be involved in this relationship since he's already had sex with his mom. But, for now he just watched to see what they were going to do next.
For almost five minutes, Zack watched Theo fuck Zoe, then Theo pulled out of Zoe and said, "I want to fuck you in the ass, baby girl."
Zoe said, "Yeah, okay dad."
Theo pulled Zoe's body towards himself so that her ass hung off the edge of the bed. Zoe grabbed her legs from behind her knees and pulled them back towards her shoulders fully exposing her brown butt hole. Theo spit on his cock that had Zoe's slippery cunt juice on it and pointed it at her anus. He rubbed the head of his cock all around her anus and then slowly pushed it in. Zoe bleated as she felt Theo's thickness penetrate her sphincter. Theo said, "I'm going to push all the way in now baby."
Zoe grunted as Theo's thick cock sunk deep into her rectum. Zoe sighed when Theo had stopped pushing in as he bottomed out so to speak, balls deep. Zack was totally turned on watching that huge black cock disappear into his mom's butt hole that he had to start jacking-off. He dropped his pants and whipped out his big cock of his own and started stroking it.
Theo started butt fucking Zoe fairly hard and fast right away. Zoe yelled out, "Yes daddy, fuck my ass, fuck me fast and hard, fuck me daddy!"
Zack really got aroused when he heard his mom yell out and watch that huge cock go in and out of her ass.
Theo yelled out, "You like getting fucked in the ass, don't you!"
Zoe responded, "Yes, I love getting fucked in the ass, keep fucking me daddy!"
Theo continued to hammer Zoe's ass with vigorous, aerobic fucking.
As Zack was watching and jacking-off, he groaned a bit too loud and Theo and Zoe heard him. They both looked towards the doorway and saw Zack with his pants around his ankles and his hand around his big cock.
Zoe screamed out, "What are you doing home so early, you were supposed to be at band practice."
Zack said, "It got cancelled."
Theo said, "Oh my god Zack, this was a secret between your mom and I, I'm sorry you had to see this."
Zack said, as he walked into the room, "It's okay gramps, I don't know if mom has told you, but she and I have sex with each other, plus I got totally turned-on watching you fuck mom in the ass," as he chuckled.
Theo pulled out of Zoe's ass and looked at Zoe and said, "You have sex with Zack?"