I owe the conception of this story to homealone_447's The Attic. I consider this to be an indirect sequel, in that character's from that story are in the background here and it largely adheres to the alien's method of propagation. The rest is my doing, enjoy.
*
Denise stood vigilant, looking outside her window, observing her neighbor, Rebecca. Only a few days ago had she deposited her 'baby' into the woman's basement. In reality it was an alien life form, a very insidious fungus that had changed her life, and of her lover, Gloria.
A few weeks ago both were normal women...human women. But no longer. Ever since Gloria discovered the fungus in her attic, both had been transformed into utter slaves, the fungus absorbing their minds, personalities and souls altogether. And it was glorious, to have every part of their being wiped away, to be left little more than a sexual shell to bring more to the Master.
Gloria sauntered into the room seductively, wearing absolutely nothing, just the way she liked it. Her nubile form stacked and delectable as ever, hips moving hypnotically and her voluptuous breasts swaying with her step. She was sex incarnate, but unlike Denise, her transformation had been more dramatic, blessed with dark, emerald skin, and pitch black eyes, she was as fearsome as she was beautiful.
"She has been marked. I can tell." Gloria whispered.
"How?"
"She has the same green rashes as this body did, before the final takeover. It is only a matter of time, she will feel compelled to give herself to the Master."
"Good."
Rebecca hurried into her house with the groceries, dropping them on the counter. Her panties were soaking, desperate to straddle the fungal stem once more. All day had she thought about this, fingering herself at work to tide herself over for the main event. She did think it was a bit strange how insanely horny she had become ever since discovering the fungus, but as soon the thought crossed her mind it was gone. She had to handle this urge fast, her son was coming home from college tomorrow morning and wanted to make him a nice breakfast.
Rebecca walked into the basement to see her pride and joy, this wondrous new sex toy. As she slipped off her blouse she couldn't help but notice the almost translucent green rashes that riddled her body. They had enlarged over the past few days, she thought to go to the doctor about it, but this thing was just too much fun to leave alone.
Green rashes aside, her body was fairly attractive. Though in her mid-40s, Rebecca was still in decent shape, and with very little sagging and stretch marks, she had no problem courting male attention. On the other hand, she often thought her ass was a bit flat, and while she was comfortable with her pert C-cup breasts, she had wished they were a bit rounder and fuller many a time.
At her disrobing, the phallus-like stem rose to the occasion, and Rebecca finally quenched the fire in her loins as she took a ride. Or so she thought. The thing was huge, filling her up beyond what she thought was possible. Her thighs quivered and her body trembled as it went as deep as it could possibly go, grinding against every pleasurable spot in her pussy, until she came, her love juices spraying all over legs and the stem. What was meant to slake her lusts only enlivened them, after that first orgasm, she started bobbing up and down, with feverish, sex crazed mania. Her delicious moans reverberated throughout the basement as she tweaked her nipples to increase the insane pleasure.
The stem itself was secreting some sort of fluid, when it hit her vaginal lips it was a cool sensation but when it was inside her...it was red hot! The euphoric contrast sent her screaming to the heavens, as she arched her back in response to the ceaseless pleasure. The orgasm had left her mind blank for a few moments, before she slid off the stem, completely spent and exhausted.
She remembered she still had so much to do. Clean sheets, wash windows...but she was simply too tired. She thought to just take a quick nap and she'll be good as new. Taking a nap right near the stem, on top of the fungus. Somehow the idea was creating little pangs of caution in the back of her brain, but she shushed it away. Just nerves. She needed her sleep, and sleep she did.