The aliens had been studying the earth for some time...

They had been looking for a way to colonise the planet, but it was clear that humans were already the dominant species with enormous numbers and aggressive tendencies. A direct attack from a small colonisation ship would almost certainly fail even with their superior weaponry.

However, while studying human reproductive activity the aliens had also discovered some potential weaknesses (particularly the male of the species). They had noticed that the males could easily be induced to deliver sperm to an extremely attractive female regardless of their bonding status. They had also noticed that the males' entire reproductive capacity was contained in two very vulnerable glands exposed between their legs.

They concluded it might be possible to genetically hijack the human species by generating a seed colony of female mutants with all the characteristics necessary to make them irresistible to male humans + one special attribute: An insatiable appetite for human sperm and testicles!

The mutant females would serve a dual purpose. Their feeding activity would terminate the breeding capacity of human males and they would use the collected sperm to reproduce themselves. Genetic information from the sperm would allow them to accelerate the invasion by breeding new females that looked similar to the local population, but had the same devastating appetite. They were designed to grow and breed extremely rapidly, feeding on a diet of pure testicular protein. Several test encounters had proven they would have no trouble obtaining an ample food supply!

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Dave had been scoping out talent in his local bar for over an hour. Most of the women were regulars he had already test driven or pros who wanted more than he was prepared to pay. He was about ready to move on when an absolutely stunning blonde appeared through the door. She wore a slinky, low cut evening dress that hugged an impeccable figure and confirmed that she had no need or intention to wear any support for her perfectly rounded D cup breasts. Her nipples stood clearly erect beneath the thin fabric and pointed directly at her target. She stepped astride the bar stool next to Dave and immediately asked "What's yours?".

Being tall and well built, Dave was used to being approached by women, but not usually in such a forward manner. "A martini in such beautiful company." He replied, slipping almost automatically into pickup mode.

They made small talk for a few minutes but she soon made it clear that she wasn't there for the conversation. She wanted SEX.

Fifteen minutes later they were in Dave's apartment. As he closed the door behind him, Dave realised he didn't even know her name. He was about to ask when she unzipped her dress and it slid to the floor revealing an ass that would make a sculptor weep. It was perched on a pair of immaculately curved thighs that she spread just wide enough to reveal a perfect pair of plump pussy lips. Dave could just make out a glistening trickle of juice in the crevice between them. Then she turned on her toes to reveal those magnificent breasts and pouting nipples.

Dave was instantly rigid. He began to rip off his jacket and shirt. He felt the woman grip the waistband of his trousers and yank them down. He was surprised at her strength and she caught him off guard as she tightened his belt around his ankles. She had no trouble pushing him backward to a seated position on the end of his bed.

"OK" Thought Dave, "She's a bit kinky, but I'll go with this if she wants to do all the work."

He leaned back on his elbows and prepared to watch the show as his cock stood flagpole straight above his belly.

Staring hungrily into Dave's face, the woman lowered herself slowly downwards. She caressed his thighs with her fingertips and pressed gently on the inside of his knees. Dave responded by spreading his legs as best he could with captive ankles. The awkward position pushed his cock up towards her face and lifted his dangling balls. Those balls ached with the weight of accumulated sperm.

The woman gazed hungrily at Dave's lewdly exposed genitals. His scrotum tightened as he watched her inhale the rich scent of his gonads and he prepared himself for the blowjob of a lifetime!

The woman lowered herself again until her arms rested over Dave's wide spread knees. She grasped his wrists with her hands and pushed them down onto the bed. Her unusual strength became apparent again and Dave realised he was held firmly in position. In any other situation, he might have panicked, but as she lowered her glistening lips slowly toward the distended tip of his cock, his mind was on other things.

When her lips made contact, she opened her mouth wide and Dave noticed the she had a particularly long tongue. He could hardly wait to see how she used it! He also caught a glimpse of something else. It seemed like a long thin appendage protruding from somewhere in the back of her throat. At first Dave concluded it must be some kind of deformity, which seemed rather odd for a woman who was otherwise so perfect. He would soon discover that the appendage was no deformity. It was a feeding tube!

As the woman's lips encircled his shaft, her tongue began to move around his cock, swirling and licking, lightly at first, but with increasing urgency. Dave felt a surge of heat flooding into his cock. For a moment he thought he was going to cum, but his cock just kept getting harder and harder. Dave could not have known that her saliva contained a powerful sexual hormone and she was working it into his rapidly expanding cock. Thick veins pulsed along his shaft and the head fattened to a bulbous knob in her mouth.

When he was fully erect she began to work her lips up and down his aching shaft. Dave had never met a woman who could take all of his 8 inches into her mouth, but this woman managed it on her first attempt! With each stroke, she took every inch of his cock. Her lips reached the base of his shaft and she swallowed him whole. Dave was sure he could see the shape of his cock head moving in her throat!

The woman began sucking rhythmically and increased the suction with each stroke. Dave felt the familiar tension building in his balls. His cock began to leak a steady stream of precum juices into her mouth. She knew instinctively how to bring a man close to orgasm and maximise his sperm production before she began feeding. The taste of his juices only seemed to intensify her appetite. She sucked even harder and Dave was soon on the edge of orgasm. His hips began thrusting involuntarily, driving his cock even deeper into her throat.

Her feeding tube tapered to a slender tip and Dave barely noticed as it slid into the opening of his penis. At first he enjoyed the unusual sensation, but as she pushed the full thickness of her sucking tentacle deep into his cock, he realised that there was something working its way into his body through his sperm tube!

Dave looked down and saw her eyes flash a luminous green. He finally realised that the woman devouring his cock was not human!

He began to panic, but his approaching orgasm and her powerful grip held him firmly to the bed. His hips writhed frantically as his helpless body supplied her with a rich stream of precum juices. His slippery secretions eased the entry of her probe. With each spasm he felt it slip a little further in. As the thickest part stretched his penis to capacity, she began to massage the underside of his cock with her tongue. She worked her way down the length of his sperm tube to the root of his cock and then with one final push…

Nnnngh!, Dave grunted and she was deep inside him.

Suddenly, he felt a squirming sensation in his scrotum. He screamed in panic, but it was too late. Her feeding tube had reached his balls and she was going to eat them alive!

The idea of an alien woman devouring his testicles terrified Dave, but to his amazement, it also turned him on! His hips jerked uncontrollably and his cock pumped harder than ever. He was lost in a mixture of ecstasy and fear.

He tried desperately to escape, but it was too late. He felt a searing pain as she plunged the tip of her feeding tube into his left testicle and injected him with saliva. The hormones took instant effect and Dave exploded into the most powerful orgasm he had ever experienced.

His first rush of cum would have filled any woman's mouth, but it was sucked directly out of his testicle and she swallowed it in seconds. Before the next spasm arrived, she injected him again. His second ejaculation was even more powerful, but it too was sucked from his body. His impaled organ produced load after load of human seed for the sucking alien woman.

As Dave's orgasm reached it's peak, she began to devour the tender flesh of his testicle. He screamed in terror, but his orgasm only intensified. His hips bucked wildly and he continued to pump sperm even as she ate. The alien woman feasted on the protein rich mixture of sperm and his most delicate meat.

When his left organ was gone, she began to withdraw. For a moment Dave thought he might be allowed to keep at least half his manhood, but she pushed in again. He tried frantically to escape but she held him down and plunged the feeding tube into his remaining testicle. He felt hot saliva flooding into his gonad and another batch of orgasmic  spasms wracked his loins. Again his body dutifully pumped sperm for her. She mercilessly emptied his remaining ball and greedily consumed the last of his reproductive organs.

Finally, when Dave's scrotum was reduced to an empty husk, she released him. Dave watched exhausted as she slowly withdrew the feeding tube from his cock and sucked it in between her smiling lips. Paralysed by fear he watched her casually dress and walk out the door.

Dave had no idea that he had just provided enough sperm to ensure a similar fate for a hundred men just like him...