Mark took his keys out of his pocket and went to unlock the door. Much to his surprise the door was already open. He walked inside telling Andrew to keep the noise down, as his twin sisters would be in bed.
But then from the silence he heard his sister’s soft voices.
“I would love to try group sex” said Katy laughing
“Do you not think it would be weird? I mean imagine another couple going at it, as you played with a guy” replied Nikki
“It would be amazing. Hearing her moans would really get me going”
“I guess it would be hot seeing two dicks hard and ready”
Andrew couldn’t help but let laugh. He stood in the hall looking at his friend’s face, awash with fear and embarrassment.
The door from the living room opened quickly. “Mark, have you been listening to us? You’re our brother that’s sick” Katy shouted at him.
“I wasn’t listening, we have just come in” he protested. “Why are you talking about that stuff with Nikki anyway?”
“She is my sister. Girls talk about things like this, and don’t pretend you didn’t like hearing our fantasies”
“Of course I didn’t you’re my sisters”
“Well now you have heard our fantasies you need to tell us yours” she said grabbing his arm and dragging him into the living room. “You too Andy” she carried on pulling him in as well.
Nikki was sat on the sofa in small shorts that showed the shape of her tight ass perfectly. She had a tight vest top on and it was clear she had no bra on, as her dark nipples showed through the pale material.
Katy walked over and joined her sister. She was wearing a tight fitting nightgown that just covered her ass. Her large breasts pressed against the soft cotton stretching it slightly.
The boys sat down nervously on the floor opposite them. Mark didn’t know where to look as he saw Nikki’s nipples standing erect within her vest top. He decided to stare at the floor.
Andrew on the other hand couldn’t take his eyes of the twin sisters. He hadn’t seen them in a while and now that they were 18 they seemed so grown up. He felt his cock twitch lightly in his jeans, pushing against the restricting fabric.
“So would you two like to try group sex then?” asked Nikki with a cheeky devilish smile on her face.
Mark once again felt his cheeks begin to blush. Was he really talking to his baby sisters about group sex or was this some weird dream. He looked up and thought he best answer.
“I guess I would give it a try. With the right people I mean. We would all have to be comfortable with one another”
“I could help you out right now if you wanted” Andrew slurred. Enjoying the torture his best friend was going through.
“Are you being serious? You’re suggesting you have sex with my sisters while I am sat here.” Mark barked, glaring at his friend.
Nikki and Katy looked at each other and shared a knowing smile. “There would need to be four of us for it to be fair though” said Katy, slowly opening her legs. She shuffled round on the sofa making sure that Mark could see up the bottom of her nightgown.
They sat in silence for a while; Mark was still trying to get his head around what was going on. He had just caught his little sisters talking about having group sex and now his best friend was suggesting he helped them out. He looked at his friend who was sat grinning like a fool. He then turned his head to look at his sisters.
Mark couldn’t believe his eyes. The first thing he saw was Katy’s soft shaven pussy lying under her nightgown. He felt his cock twitch in his trousers. “Why aren’t you wearing any pants?” he asked trying to hide his growing member.
“I never wear panties to bed Mark. Why do you like what you see? Do you want to see more?”
Katy had now slid down on the sofa opening her legs more as her nightgown rode up above her swollen mound. “We could all have some fun, no one will ever know. It can be our little secret”.
Mark’s eyes were fixed on his sisters glistening shaven pussy. He was so transfixed by this he didn’t realise that Nikki was now making out with his best friend beside him.
Nikki had slipped off the sofa and crawled over to Andrew; she kissed him gently and slid her hand up his thigh, feeling his throbbing cock within his jeans. He kissed her back, letting his hands explore the young 18 year olds petite figure. His hand slid up the front of her top and his fingers were soon playing with the dark nipples on her 32B breasts.
“Come on Mark. This is a onetime offer. Make me feel like a women, I know you want to” Katy continued lifting her nightgown over her head. She lay slouched on the sofa, naked for the first time in years in front of her older brother.
Temptation was too much for Mark and he reached out a hand placing it on his sister’s shaven mound. It was so warm to the touch, and he felt her moist lips with the tips of his fingers. Katy moaned quietly as she felt her brother’s cold hand touch her.
Nikki had now stood up and removed her tight vest top. Andrews’ eyes were fixed on her prefect curves as she turned away from him. She grabbed the top of her tight shorts and bent forwards sliding them down her thighs. She continued down, pushing her ass high in the air, her warm damp pussy just inches from his face.
Andrew leant forward taking in the sweet scent of her young pussy. He continued moving his head forward until he felt her soft pussy lips touch his. He slid his tongue along her wet lips and up to her tight ass.
Both girls were moaning gently as Andrew began to slide his tongue in and out of Nikki’s wet cunt, and Mark let his inhibitions go and slid two fingers deep into Katy’s sopping pussy.
“I think we need to see you both naked” Nikki moaned as she stepped forward.
“Yeah, we want to see your throbbing cocks” Katy moaned, gently pushing away her brother’s damp fingers.
The girls sat next to each other once again on the sofa, smiling happily as they both spread their legs wide open, gently rubbing the lips of the wet and wanting pussies.
Mark and Andrew both Jumped to their feet. They pulled off their shirts and both fumbled with the buttons on their jeans. The girls were now sliding their fingers in and out of their pussies the excitement and anticipation making them both moan loudly.
Andrew was the first to drop his jeans and boxers, revealing his thick 6 inch penis. Mark then did the same revealing his long throbbing cock. He was almost 9 inches long and stood before his younger sisters stroking his full length up and down.
The girls stood up on the sofa, turning the boys to face each other they knelt either side. Nikki grabbed her brother’s long twitching penis and looking up into his eyes she slipped the throbbing tip of his cock deep inside her warm mouth. Katy didn’t want to be left out and stretched her mouth around Andrews’ thick cock.
The girls sucked and slurped on the cocks, switching between them like they had done all of this before. Allowing themselves to get carried away the girls continued to alternate between the two huge dicks, but were now gently rubbing each other’s clits with their spare hands.
Nikki was the first to find it all too much and moaned loudly as an orgasm shot through her body. She forced Andrews cock deep into her mouth muffling her loud moans and letting him feel her orgasm. She rubbed franticly at her sister’s swollen clit and Katy was soon screaming with pleasure, tugging hard at her brother’s long cock.
The girls kissed each other gently as they recovered from their first orgasms of the night, letting the boys tug hard on their cocks as they watched the two sisters teasing them.
“Which cock do you want first” Nikki whispered in her sister’s ear.
“I’ll show you” her sister replied climbing to her feet….
To be continued.
Via: https://www.lushstories.com/stories/incest-fantasy/join-the-family-fun