The alien was a member of a highly evolved race but dwindling race who unbeknownst to the world's public had just conquered the earth. They privately demonstrated to the world's major powers just how futile an armed conflict against them would be. They were actually a peace-loving race and believed it was their mission to stop warlike tendencies among the planets in the galaxy.
However they would allow us to continue governing ourselves provided we provided them with willing human females (sometimes unsuspecting women who wished to study this alien species!) with which to develop methods to breed alien/human hybrids. Over the last few hundred years, their females had been slowly growing sterile.
All their scientific knowledge couldn't stop this and finally all their females became sterile and no longer capable of producing offspring. Trying to reproduce strictly through genetic engineering wasn't a solution and their very DNA started showing signs of inevitable decay. So these hybrids would eventually produce a new race and provide a way for their civilization to go on, although in a different form.
When doing tests on abducted humans, they found that even genetically mutated male human sperm could not fertilize their females. However male alien sperm when genetically altered was capable of impregnating a human female. However no physical sexual contact was necessary to produce offspring. It could all be done in a science lab.
However when one of the alien males decided to try physically mating with a human female, he quickly discovered that mating with women was much more pleasurable than with their own kind. Other alien males found out, and they insisted in actually mating with human females.
So the female staff at the various facilities now had to deal with horny alien males literally jumping the female staff. Oftentimes, new female research staff and staff assistants were not fully briefed or not had time to be briefed before they had an encounter. Secretive hushed whispers soon started circulating among earth women in these facilities around the world that this was not necessarily a bad thing. As these reports got out in the public they were quickly discredited and soon forgotten, but then often re-emerged again like a Phoenix.
It was not known until later why the women only initially complained, but not strenuously, and each dropped their complaints after the first voicing and wished it dropped. After the reason was discovered, then respiratory and skin contact precautions were initiated but these precautions slowly became forgotten as time passed...
The male Saurians were a physically large, powerful being with a male average height of seven feet, two inches while their females were average human female height.
Karen, the head researcher of this facility was in late with only a female doctoral assistant working with her in the lab. The woman, fresh out of graduate school had already been shown taped video footage of many women having sex with the very alien currently in their lab. Of the peculiar things that were discovered with the aliens was that they were multi-orgasmic, other things of a sexual nature were discovered that helped keep the whispered rumors alive and very well. The Alien being had been following this research technician all day around the enclosure.
So as Karen sat quietly reading a report in the control room, she was surprised to see that the woman was quietly entering the alien's enclosure. Through a concealed color high resolution video camera, equipped with highly sensitive directional microphones, Karen saw the woman checking to see if she was alone. The woman then walked straight into his enclosure. Though obviously pleased, the alien kept his cool about her being there and approached her calmly.
To Karen's surprise, the woman then started to strip. Once naked, she was quickly on her hands and knees waiting for him. The much larger Saurian then mounted her with great gentleness. His midsection was now nested against her back. His genital area was slightly behind and above her firm round buttocks. His member was completely enclosed within a slit on his lower abdomen, concealing the actual true size of his member until aroused, and had now just started to peep out.
As it emerged the member crept out over her buttocks emerging toward and then over her tailbone, starting to show the evidence of it's true enormous size. She then bent her back downward slightly, which raised her butt cheeks upward inviting the emerging male's organ into her.
She gently starting lowering and then raising her buttocks, caressing his member, then she started to bend her back a little bit lower with each up and down motion until her vagina was rubbing the partial length of his shaft. Her labia had already engorged and swollen, her swollen, distended labia lips visibly pulsating, had spread apart like the petals of a flower allowing his thickly ribbed member to slide over her opened cleft, over her clitoris and then back down bumping her clitoris and inflaming her desires.
His very large sex organ continue to emerge out from the slit on his lower abdomen, and then the tip of his member probed at the open gap just at the base of where her buttocks separated and her vaginal opening lay.
The insertion was very gentle and slow as the 14 inch long; 21/2 inch thick ribbed organ that was visibly swelling to an even greater girth began to slide deeper into the woman with each gentle repeated thrust that eased a little more in with each thrust. A low guttural moan escaped her lips as it was slowly buried deep inside of her. The smoothness with which the two only distantly related species had coupled was amazing. As the girl started rocking back and forth onto the cock, it swelled till its girth was 4 inches across!
Slowly at first and then with increasing intensity, a behavior their species shared then set in. That being the rhythmic thrusting method of copulation that both species shared. Her outer and inner labia clung to the massive organ as it was pumped in and out of her. The fucking was very human in duration and surprisingly tender.
The slit on the Suarian also acted as a large suction cup, repeatedly sucking and then releasing her vaginal lips, labia and clitoris, swelling and engorging them, pulling them outwards as he withdrew his member, the suction breaking audibly as his length emerged and then reattaching again as he thrust his member back in.
It was obvious to Karen that the woman was more than enjoying the sex. Karen was no prude, she and her boyfriend watched porn flicks regularly and no porn acting compared with the feelings this woman was exhibiting.
She was rhythmically raising her butt in response to his shaft being plunged into her from behind. Her breath occasionally got caught in her throat as the male organ was driven deep into her eager and willing body. He was breathing hard too, his lust being expended on his very willing and enthusiastic partner.
The alien as always was fully enjoying fucking with a human female and all the human females enjoyed and desired it tremendously as the Saurian's secreted a sexual pheromone from their skin pores as well as from their member that incited desire in females.
This was the secret that became known with a whisper that reached around the world.
Also the Saurian body temperature was 26 degrees warmer than humans, which further increased the passion as the hot member slowly pistoned into her contracting pussy, almost withdrawing then plunging deep into her rhythmical contracting depths.
Finally, the girl climaxed thunderously. Her head dropped, and she let out a long, slow extended breath. As if blowing on a hot bowl of soup. However the Alien wasn't finished with her. He lifted her up onto a table. She then laid back and spread her legs apart. Her pubic hair was neatly trimmed with just a small triangular patch showing above her vagina exposing her moist vaginal opening. Her lean muscular body heaved with breathes of excitement as she waited for him to enter her again.
She literally jumped as the tip of the hot moist organ made contact with her wet openly pulsating pussy. The alien then gently grasped her calves and spread her legs apart and pressing her knees up towards her well endowed chest. Then he slowly entered her willing body.
The Alien could feel her vagina open and stretch as he slowly introduced his member into her. The member was very hot, but he was having trouble getting the entire 14 inches of his swollen thick member into her.
However, shortly after it squirmed around a bit, this stimulation along with the thickly secreted sex pheromones from his member, increased her production of vaginal fluids, and it quickly slipped completely inside her.
The alien then finally began to aggressively fuck her. Occasionally his member would slip out and bang against her tightly puckered anus and then he or she would reinsert it into her pussy. Her vagina was comfortably tight so that her vaginal walls pressed tightly on the shaft and caressed it with strong rippling muscle contractions into her depths.
The sex pheromones that were being secreted in thick copious amounts were running down over her anus, stimulating it and causing involuntary muscular rhythmic contractions of the anal muscles and sphincter.
Her swollen pulsating labia lips clung to the pistoning organ as the ring of muscles around the vaginal orifice gave extra firm squeezes. Karen was mesmerized by the sight of these two beings locked in mutual pleasure, her own desire strongly building. Suddenly the intern's hips began to thrust more aggressively as she slowly rose to another massive orgasm.
As she peaked repeatedly under the tenacious, but slow and tender, thrusting, she began making small grunts as each breath was expelled. Finally, as his own pleasure became too much, the alien slowly decreased it thrusts and ejaculated deep inside her as he leaned over and held her close.
The secretions from his member had actually caused her cervix to dilate allowing his massively thick member to penetrate deeply into her womb. From the high gain directional microphones mounted to the cameras, Karen could hear her lab assistant moan
His cum is so HOT! I can feel it squirting!
It feels so powerful!
He's cumming, I can feel him squirting like a firehose!
He is shooting into my womb!
So very Hot ... so good."
GAWD he is in so DEEP!
She elicited a moan as she felt each ejaculation which continued for several minutes ... pumping copious amounts of cum deep within her.
The tip of his member repeatedly flexed upwards two inches from the force of each of his powerful explosive ejaculations erupting from the tip.
She deeply moaned each time she felt the tip moving deep within her and then again from the hot cum blasting onto, then rebounding off the walls of her womb.
Two unique evolution adaptations had evolved in the Saurian species to ensure impregnation: 1. a very long, massively thick cock that could actually enter the womb and, 2. a very large momentary bulge would form near the base of his cock with each powerful pulse of his ejaculation that ensured that no semen would backflow out of the vaginal canal until the womb was full of fluid and his member withdrawn.