Please first read "My Son The Inventor - Ch1 and 2"



Barry loved his girls so being a gentleman he let them sleep away the afternoon and at 5:30PM he started cooking supper. Well cooking would be a stretch but he did make a salad, opened a bottle of wine and barbecued ribs and portobello mushrooms.



At 6:30PM Aunt Becky stumbled down to the kitchen in a flimsy nightie. Barry went to wake up Mom but she was already coming to the kitchen in her robe. He poured them a glass of wine which they both drained sticking out their glass for a refill. Most unusual for his girls but he supposed abnormal behavior should be expected.



After they had eaten their energy seemed to come back and they were all smiles but still looking a bit dazed. While they were having ice cream for desert Barry said he needed some more help. Both their faces went white but he quickly said it was research and did not involve a sex machine.



His girls breathed a sigh of relief. The comedian Becky made her hands into two paws on each side of her face and twitching her nose said I will be his guinea pig, they all laughed. Barry said and a very sexy guinea pig at that but I need both of you tonight. He looked at Maria and she smiled nodding her head.



Barry explained that he had an idea for a new sex machine but needed more first hand experience. He said he wanted to make a machine that could emulate eating pussy. He knew he had struck a cord the way their butts started to gyrating.



They all went to Becky's room as she had the largest bed in the house. After stripping they sat on the bed and Barry asked them each to describe their favourite oral sex techniques. The ones which made them come the hardest.



Aunt Becky said she liked two pumping fingers hooked so that they massaged her gspot. While a mouth sucking the hood of her clit alternated with a flicking tongue directly around her nub.



She wanted the pumping finger fuck to be at the speed matching her directions. She liked to get to a peak and then slow down then get to the edge again several times for a harder climatic crescendo.



Maria said she loved a flicking tongue just below her clit with rotating fingers fucking her fast and deep. The finger fucking was to build her climax up while the tongue flicks was a tease. When she gave the word she wanted her clit sucked hard with lip vibrations, the harder the better.



Barry asked that Aunt Becky eat Mom to climax so he could see if he really understood. Maria looked disappointed but Barry gave her a reassuring smile and wink that he would be involved soon enough.



Maria moved to the head board propt up on pillows then spread her legs for Becky. Becky leaned forward and gave Maria a tongue laden kiss then kissed down to her tits and bit her nipples. Her hands stroked all over Maria's body, slowly working her mouth down to Maria's pussy.



Maria's eyes closed sinking into the sensations that her sister was creating. Soon Becky had Maria's lamblia spread exposing her clit flicking her tongue like a snake. Then Becky inserted two fingers into Maria's pussy and started pumping building up speed to a chorus of moans, faster, just like that ...



Eventually Maria's pelvis was pushing into her sister's face. Becky started pistoning her fingers and Maria yelled FUCK ME! Becky clamped onto Maria's clit and hummed hard. Maria's gave a primal cry and arched her back driving Becky right off her clit.



When her ass fell back on the bed she was shaking like jello with random stomach muscles twitches. Becky leaned back slapped Maria's clit inducing one more spasm then said try to out do that sis. Maria groaned give me a bit to recover.



Barry knew that this machine was going to be complicated and needed a computer control system which appreciated a women's need to control the stimulation while not being intrusive to her pleasure.



While Maria recovered Barry asked Aunt Becky if she did anything special over what Mom had already described. She shrugged and said not really she just listened to Maria's breathing and commands.



That gave Barry an idea and he excused himself saying he would be back in a second. He returned with a portable recorder attached to a Mindflex EEG game controller. He placed it on Aunt Becky's head and asked his Mom to eat out her sister.



Maria knew Becky's oral predilections as well as Becky knew hers. Soon Becky was panting and giving Marie orders like a orgasmic field general. Maria followed her sister's orders as previously described then on cue went in for the climatic juggler.



Becky arched like a contortionist shaking out a steady stream of come onto Maria's face. Maria sat up and used the bed covers to clean up Becky's come covering.



Barry told them he was turned on big time and asked Mom if her son could practice eating at home. Marie replied Barry you can make your Mommy come anytime. She moved into position and donned the Mindflex.



Barry took hold of Mom's feet sitting up on his knees and kissed them sucked on her toes. Auntie shook her head and smiled at him, wishing her toes where getting the Barry treatment. His hands massaged her legs and even pushed forward to lightly brush her pussy. Mom looking on thoroughly enjoying her son's attentions.



Barry let go of her toes and started kissing the inside of her legs leading to her pussy. When his face was close enough she felt his hot breath on he pussy he skipped to her stomach. He kissed her breasts and bathed them with his tongue and a hand massaging the other one pulling her nipples until they were tender.



Barry left her nipples then kissed her neck and mouth with such passion that she could not catch her breath. Maria wanted her boy to make love to her for so long and now she was getting more than she had hoped. When the kiss broke he sprang down to her pussy doing all the things Maria said she liked.



Barry's quick move was such a surprise that she had a small spasm as soon as his tongue started flicking the underside of her erect clit. As his two finger caressed her pussy walls she tried to raise her pelvis but he pushed the other hand down on her mound.



She started to shake as the downward pressure increased the sensation of the finger fucking taking her arousal to new heights. Barry pumped and twisted his fingers for all he was worth.



Maria gave Barry the command MAKE MOMMY COME! Barry pursed his lips on her clit and made his lips vibrate very fast. She screamed so loud and long that Becky put her finger's in her ears. Barry kept licking and pumping his fingers until Becky pulled him off Mommy.



Barry gave his Mom a loving kiss saying I hope your baby boy has made you happy. Soon Maria was smiling and kissing back. She looked into his eyes and said please fuck your Mommy and give me your cum.



With that Barry put his hands deep in her hair at the back of her head. Then he literally pick her up by her hair dragging her off the bed with the Mindflex attached and recorder cable stringing out. He pulled her to the vanity swiping away the items on its surface. He bent her over facing the mirror, spread her legs and enter her hard.



Aunt Becky was in shock this looked brutal but as he entered her Maria said fuck me Barry, please fuck me. What happened then was the most vigorous fucking Becky had ever witnessed. Mother and Son had their eyes locked through the mirrors reflection except the times that Maria came and lost focus. All the while Maria begged Barry to keep fucking Mommy.



Barry finally yelled I am cumming and thrust very deep and his ass muscled contracted with balls rising up and down. Maria yelled Oh god over and over thank you for giving Mommy my son's incestuous seed.



Barry collapsed over her back and eventually slipped out. He left Maria propt up by the vanity and moved to the bed where Aunt Becky was still in shock. She shook her head and said Barry anytime you want to fuck me like that just do it no warning required.



When Barry had recovered a bit he got up, turned off the recorder, removed the Mindflex and brought his well fucked Mom to the bed. Both girls cuddled up to Barry and they all fell asleep.