1 comments/ 88945 views/ 33 favorites Aliens Use Sex to Invade Humans Ch. 01-02 By: walterio Author's note: I received an e-mail requesting that I write a story about aliens taking over humans and creating insatiable sexual desires. The person requesting this story had read another story on Literotica entitled Hosts. He was disappointed that the author of Hosts did not write any more chapters after the first submission, which is why he asked me to write about this topic. It is my first venture into this story category so let me know what you think. INTRODUCTION Four astronauts aboard the international space station are inhabited by alien hosts who use human sexual desires to re-populate their alien presence. The crew is returned to earth and after being briefed by the space agency they all return to their former lives. The alien's continue to use their human hosts to recruit other humans through the exploitation of sex. Chapter 01 -- The International Space Station Chapter 02 -- Astronauts are debriefed and return to duty Chapter 03 -- Rachel returns to her family life Chapter 04 -- Aaron meets his son's roommate Chapter 05 -- Carl visits a gay bath house Chapter 06 -- Sam resumes his private practice Chapter 07 -- The alien population continues to grow using humans as hosts * CHAPTER 01 - THE INTERNATIONAL SPACE STATION Aaron Peters had just re-entered the space station after making a routine maintenance check of the exterior. The space shuttle would be arriving in week with the replacement crew and to take Aaron and his fellow astronauts back to earth. Aaron's exterior inspection was to verify that the space station did not need any external repairs or parts before the space shuttle launch. He never noticed the alien visitor that had attached itself to his space suit. Aaron stripped off his space suit in the sterilization area and cleansed his body before putting his on his in flight uniform. As he cleansed himself he thought how his life had changed aboard the space station. Aaron and Captain Carl Roberts had become very close; in fact they had become lovers. Aaron still remembered the first time when Carl had given himself to Aaron both orally and anally. Aaron also remembered vividly the first time that he took Carl in his mouth and the pain he experienced when he lost his anal virginity to Carl. Aaron had never had a male encounter before Carl and he still did not think of himself as gay. Maybe it was because his fellow astronauts Rachel Cummings and Dr. Sam Leonard had sex together every chance they had. They were like rabbits those two and Aaron often wished that he was in Sam's place and that he was fucking Rachel. Aaron was in a constant state of horniness thinking about Rachel and Sam which is why he probably was receptive to Carl's advances. Carl however was a master of seduction and he had proved to be an excellent lover. Aaron was deep in thought when the alien stowaway left the spacesuit and adhered itself to Aaron's body. The alien had been blown toward the space station when its planet exploded scattering all its inhabitants all over space. The alien moved undetected along Aaron's body searching for an accessible orifice to enter the human form. The alien was in need of nourishment and sought to become a parasite in a host body. Once inside the host the alien would become capable of producing more alien bodies. The alien located an opening in Aaron's right ear and entered it rapidly. Aaron felt the intrusion and rubbed his ear quickly but the alien had already wormed its way inside. Once inside the alien moved through Aaron's body and located the place where it could nourish itself. Aaron had felt a sharp pain and then some discomfort in his ear. He decided that he would have Sam look at it later. Aaron put on his Lycra tight fitting uniform and entered the main area of the space station. His ear was starting to feel better but there was something strange happening to him. The alien was releasing a substance in Aaron's body that had the effect of a sexual stimulant. All of a sudden Aaron was obsessed about sex and he had a throbbing erection. Aaron's cock felt bigger and stiffer than ever. Aaron looked down at his cock straining to get out of his uniform. The outline of his cock was clearly visible and it looked like he had a pipe in his pants. Aaron was still worried about his ear so he decided to have Sam check him out right then. Aaron still had no explanation for his body's recent sexual reaction. Aaron entered the medical area and he stopped in his tracks. Rachel was on the examination table on her back and Sam was between her legs. They were both naked and Sam was drilling Rachel's pussy with his rock hard cock. Aaron watched the attractive couple fucking on the exam table and then he felt his own cock straining against the fabric of his pants. Aaron reached in his pants, fished his cock out and stared at his member in disbelief. His cock had grown to at least 10" long and 6" around. How was that possible? It had always been average at 6" long and about 5" around. The alien had taken over Aaron's body and looked through Aaron's eyes at the other two humans engaged in sex. The alien had Aaron focus on Sam's asshole and Aaron stared at it as he watched Sam fuck Rachel senseless. Aaron moved toward the couple on the exam table and he picked up a tube of lubricant as he approached them. Aaron greased up his cock thoroughly and then under the control of the alien, Aaron leaped up on the table behind Sam and buried his cock in Sam's asshole. Sam screamed out loud as his asshole was stretched beyond belief. The pain was excruciating and tears welled up in Sam's eyes when he felt the huge cock enter his rectum. Sam tried desperately to dislodge Aaron but Aaron under alien control was too strong for Sam. Aaron held Sam in a vice like grip as he drilled Sam's ass taking the doctor's anal virginity. Aaron felt a tremendous pressure in his balls and then he ejaculated into Sam's ass. Aaron grunted and Sam cried out as Aaron flooded Sam's rectum. Aaron seemed to cum for several minutes as he unleashed a torrent of cum into Sam's asshole. Unbeknown to Sam a number an alien body entered Sam's rectum and made its way into Sam's body. Sam was still in shock from being fucked in the ass and he felt as if a fire hose had been shoved in it. Then a strange feeling came over Sam as he felt Rachel's pussy tighten around his cock. However it wasn't Rachel's pussy getting tighter it was his cock getting longer and thicker. "Oh Sam, what's happening? Your cock is growing in my pussy. I feel so full. It feels so good. Fuck me Sam keep fucking me!" Rachel pleaded. Rachel then noticed Aaron behind Sam but she didn't care at that point. "Fuck me Sam, fuck me Aaron, fuck me both of you," she cried out. Sam began to pound Rachel's pussy and in doing so he impaled his ass on Aaron's cock again. Aaron remained still and let Sam do all the work this time. As Sam thrust into Rachel, Aaron's cock slid part way out of Sam's ass. Then when Sam withdrew slightly from Rachel's pussy he impaled his as on Aaron's cock. Sam then felt his balls tighten just before he ejaculated into Rachel's pussy. Sam filled Rachel's pussy with more cum than he ever had and Rachel's eyes widen in surprise as her pussy was flooded with the male seed. Sam stopped moving momentarily but Aaron picked up the pace and fucked Sam's ass again. As Aaron was fucking Sam, Rachel felt a strange aura take over her body as an alien form had made its way into her body. Her tits and nipples ached and she realized that her breasts were getting bibber and the nipples were getting longer. Rachel's pussy was on fire and she screamed out for Sam to fuck her. The three of them became insatiable as the aliens controlled their bodies and they felt as if they could fuck and cum forever. Sam begged Aaron to give his ass a break so Aaron pulled out of the doctor's ass. Aaron stared at his cock, which looked huge and menacing, as he decided what to do next. Aaron then had Sam rollover on the table keeping his cock in Rachel's pussy. Then Aaron greased his cock again and this time he plunged it into Rachel's asshole. Rachel screamed as the searing pain ripped through her. However the pain was brief and then Rachel yelled for both of them to fuck her. Sam drilled her pussy as Aaron drilled her ass and Rachel just screamed for more. Carl heard the commotion coming from the medical area of the space station and he decided to investigate. Carl entered the area and he was stunned to see Rachel being double fucked by his crew. Carl's cock got hard and he decided to get in on the action. Carl moved in front of Aaron intending to put his cock in Aaron's mouth but Rachel reached up and took a hold of Carl's cock and guided it into her mouth. Carl started to protest but thought better of it and let Rachel suck his cock. The alien in Rachel's body took over and Rachel took her mouth off of Carl's cock. She then reached up and pulled Carl's face to hers and kissed him deeply shoving her tongue into his mouth. Carl, repulsed by the female kiss, tried to pull away but Rachel was too strong. Carl felt Rachel's oral fluids enter his mouth and she drove her tongue into him forcing him to swallow. Rachel released Carl and he stepped back and stared at her with contempt. Then just as it had happened to Aaron and Sam, Carl felt his body change. He suddenly felt stronger and he was astonished as his cock grew in size before his eyes. Carl watched as his cock grew to at least 10" in length and swelled to 6"around. He could not explain why his body was changing but he was thrilled with the increased size of his cock. Rachel then pulled Carl's cock back to her mouth and Carl at this point did not care who was sucking him off, male or female. Carl felt his bloated balls tighten and then he ejaculated into Rachel's mouth. Rachel gulped down every drop of Carl's cum and then she felt Aaron and Sam cum in her asshole and pussy. Rachel went wild and she kept cumming and cumming as if there were no end to it. The four of them continued to have sex for hours with Rachel as the focal figure. The three men took turns in her pussy, mouth and ass. When they were finally done they looked at each other curiously and they then realized that they would never be the same again. Each of the men had cocks that were identical in length and girth. They were all fitter and stronger and had an insatiable sexual appetite. Rachel's breast had developed to a full 36C and they were firm with extended nipples. For the next several days before the space shuttle arrived with the replacement crew, the four of them had sex for hours upon hours each day. They hardly ever wore their uniforms and they remained naked most of the time. Finally the shuttle arrived to take them back to earth and the replacement crew was impressed with the physical condition and appearance of Aaron, Sam, Carl and Rachel. Of course the aliens inside the host bodies would travel to earth and seek to populate more humans which they would do using the astronauts as sex objects. A few alien bodies remained at the space station to eventually take over the replacement crew. CHAPTER 02 - ASTRONAUTS ARE DEBRIEFED AND RETURNED TO DUTY The space shuttle returned to earth and it was all the astronauts could do to refrain themselves from some form of sex while on the shuttle. The alien bodies within their hosts sensed the astronauts struggle with morality and actually helped them maintain a professional image. Each astronaut was debriefed by a NASA official and the officials were very impressed with the crew's fitness. They all seemed stronger and trimmer since they began the mission. After a few days of debriefing the astronauts were allowed to return to their normal lives although nothing would ever be normal about their lives from her on. Before they reunited with their families and friends the astronauts spent one more night at the NASA building with sleeping accommodations. After dinner that night they met in Rachel's room where they unleashed days of sexual frustration. Within minutes of entering her room the three men were fondling Rachel's body. Rachel squirmed with desire as they ran their hands all over her. They groped her breasts and squeezed her ass. Then they began to remove her clothing. First her blouse and bra came off and a set of hands rubbed her tits. Rachel reached for the hands grabbing her tits and then she felt her pants being lowered. Her pants were tugged down her legs. It was a tight fit as it was pulled over her buttocks and down her legs. Rachel almost fell with the pants around her ankles but Carl held her from behind and his hands covered her breasts. Aaron pulled the pants off of her legs leaving Rachel dressed in only her panties. She looked very sexy like that and the men felt their erections pushing through their pants. Aaron was now sucking on Rachel's tits and teasing her nipples with his teeth. Rachel faked fighting it but she was getting excited and she knew her pussy was wet. Rachel then felt Carl behind her and he pulled her panties down over the cheeks of her ass. Her pussy was still covered but her buttocks were bare. Carl then massaged her fleshy ass cheeks emitting a moan from Rachel. Sam then took hold of her panties and peeled them down to her knees baring her neatly trimmed pussy. Sam ran his fingers over her vulva causing Rachel to groan. She knew her pussy was dripping wet with desire and that Sam would be able to sense her state of arousal. Sam then removed Rachel's panties from her body leaving her standing naked except for the blouse around her wrists. Rachel was now completely naked in front of the three men. Carl moved to one side of her body and Aaron moved to the other side. Both men unfastened their pants and pushed them along with their underwear to their knees. Their impressive hard cocks sprung lose and stood out from their bodies. Carl grabbed one of Rachel's buttocks with his right hand and one of her breasts with his other hand. Aaron on the other side of her body grabbed one buttock with his left hand and a breast with his right hand. The two men fondled and squeezed the big tits and fleshy buttocks in their hands. Rachel's hands instinctively took a hold of both hard cocks and she stroked them slowly as the men played with her body. Sam rubbed his hand over Rachel's vulva and then he parted her labia. He dipped his fingers into her pussy which was now soaking wet and in dire need of attention. Sam fingered Rachel's pussy as the others fondled her body and she stroked the two erect cocks. Rachel felt an orgasm approaching and she groaned when it hit her. Her body shook slightly and shivered as she reached a mild climax. Sam felt her orgasm and smiled as he knew what to do next. "Let's take her to bed," Sam announced. Rachel was guided into the bed on her back. The three men stripped quickly and Sam was the first one between Rachel's legs. He was rock hard and he eased his impressive cock into Rachel's pussy. Rachel gasped when she felt the big cock enter her and she wrapped her legs around Sam's torso. "Oh I love your new big cock," Rachel gasped. Sam started pounding away at her pussy with his big cock as he was really turned on and close to cumming. Then his body stiffened and he ejaculated deep into Rachel's cunt. Rachel held the astronaut tightly with her arms and legs as he shot streams of cum into her womb. Even though Sam came quickly, Rachel knew that she was in for a long night again with the three men. Sam pulled out of Rachel's pussy and Carl was there immediately to take his place. Rachel felt another big cock fill her cunt and she wrapped her legs and arms around Carl. "Oh I like your big cock too," she gasped again. Carl fucked Rachel with rapid strokes as he too would not last long. His body soon stiffened and then he filled Rachel's cunt with his load. Her pussy was overflowing with cum and it began to trickle out of her. As soon as Carl pulled out of her Aaron was in her and he too fucked her hard and fast before shooting his load into her. Rachel also orgasmed and she wrapped her arms and legs around Aaron and squeezed his body as she climaxed. Aaron felt her cunt muscles working his cock as she came. Aaron let Rachel relax before he pulled his cock from her pussy. The three men watched as cum trickled out of Rachel's cunt and coated her inner thighs. All three men were still erect and their big cocks dangled in front of them. Rachel stared at the impressive cocks that were now above their former average size. She guessed them to be in the range of 10-11 inches long and at least 6 inches around. Rachel liked their new cocks at this size. Sam crawled back between her legs and he slipped his cock into her cum filled cunt. Rachel knew that Sam would last longer this time and that she would probably orgasm again before he came. Carl knelt along side Rachel's head on one side and offered his cock to her mouth. Rachel turned her head to one side and took the big dick in her mouth. Aaron moved to the other side of her head and Rachel took turns sucking on Aaron's and Carl's cocks as Sam fucked her. Rachel had multiple orgasms before Sam came again and her pussy was cum drenched with commingled juices. Then it was Carl's turn to fuck her again and Sam had her suck his cock clean of their combined juices. Rachel sucked on Aaron's cock and Sam's cock as Carl fucked her silly. Rachel had more orgasms and she felt weak and lifeless by the time Carl fired a barrage of cum into her pussy again. Then it was Aaron's turn even though Rachel had nothing left. She lay almost lifeless as Aaron fucked her until he came again. Sam then searched through her purse and located a bottle of hand lotion. The lifeless body of Rachel was then rolled over and her hips were pulled up so that her big ass stuck up in the air. Sam got behind Rachel and he began to fondle her ass and tease her nether hole. At the same time Carl got in front of Rachel and fed his cock to her mouth. Rachel sucked on the big dick as Sam fingered her asshole and pussy at the same time. He had put an ample amount of lotion in her asshole and his finger moved around easily. Satisfied that she was ready, Sam put lotion on his cock, spit in his hand and stroked his cock making it very slick. He knelt behind Rachel and eased his cock into her asshole. Rachel gasped on Carl's cock when she felt the big cock worm its way onto her ass. Rachel had been butt fucked plenty of times since she lost her anal virginity on the space station so there was no pain for her just that familiar sense of fullness. Sam fucked her slowly as she sucked on Carl's cock. Aaron moved along side her and he played with her big tits as they hung down toward the bed. Sam tried to prolong fucking her ass as he loved watching his big cock slide in and out of her anal passage. He squeezed her fleshy buttocks as he fucked her ass and he like to see them jiggle when his thighs slapped against them. Rachel knew that Sam intended to cum in her ass and she loved the wicked feeling of cum shooting into her rectum. Rachel felt Carl's cock pulsate in her mouth and she sensed that he would cum before Sam came. Carl held Rachel's head gently in his hands as he erupted in her mouth. Even though it was his third load there was still plenty of it. Rachel gulped and swallowed as quickly as she could as jet after jet shot into her mouth. Carl's ejaculation finally subsided and Rachel sucked on his cock gently milking the remaining cum from his shaft. Carl was thrilled that she swallowed his load just as his gay lovers would. Rachel then felt the first jolt of cum shoot deep into her rectum as Sam began to ejaculate. He fired five or six streams into her anal canal and then the barrage stopped. Rachel felt the fullness in her ass and she used her anal muscles to squeeze every last drop of cum from Sam's cock. His cock eventually softened and slipped from her asshole with an audible pop and a trail of semen oozing out of her anus. Rachel relaxed for a minute and she felt Sam's cum trickle down her inner thighs. Aliens Use Sex to Invade Humans Ch. 01-02 Rachel did not relax long though as Aaron was behind Rachel and he pushed his impressive cock into her ass. Aaron was excited to be in her ass again and he fucked it fast and furious. Aaron too loved the way her buttocks jiggled as he slammed into her seeking another ejaculation. Rachel was presented with Sam's cock to suck clean as Aaron drilled her ass. Rachel sucked on Sam's soft cock and she liked the feel of it in her mouth. Then she felt Aaron stiffen and cum in her ass. Once again she was surprised with the force and the amount of semen that the men generated when they ejaculated in her. Rachel instinctively used her anal muscles to milk Aaron's cock dry before he finally slipped out of her ass. The aliens used their powers to rejuvenate the host bodies and they were all ready for more action even though they had all cum three times already. Rachel allowed her body to be maneuvered into position as her pussy was guided onto Sam's cock as he lay on his back. Then Carl shoved his lubricated cock into her ass and Aaron pushed his cock into her mouth. Rachel allowed herself to be used by her three colleagues and this time she was thankful to have a cock in her pussy again. She too was horny again and her clit needed a good scraping. The three men fucked Rachel for a long time before they finally came again. She had had multiple orgasms and she had collapsed on Sam underneath her. Rachel had nothing left and she lay still as the three men sought their pleasure. Her mouth just closed around Aaron's cock as he fucked her face until he came in her mouth. Instinctively she swallowed his load. Carl was the next to cum and he shot his wad in her ass which was filled to overflowing. Finally Sam came in her pussy and then Rachel moved off of him and lay face down on the bed. The aliens decided that their hosts had had enough for one night. The three men left Rachel in bed and returned to their own rooms. Tomorrow they would return to their families and lifestyles unaware that the aliens had even more surprises for the crew in the days to come. THE NEXT CHAPTER Rachel returns to her husband and 18 year old son. She kisses both of them passionately as she had not seen them in months. However unbeknown to her she passes an alien substance on to both her husband and son. Her son watches his mother and father engage in sex and he feels compelled to join them. Rachel's husband in turn passes the alien substance onto his mistress and her son passes it onto his virgin girlfriend.