Forever Hung (Part 9) [sci-fi] [slow burn] [all characters over 21] [MF, MF] [voyeur]

I’ve no idea when the professor found time between his lab work and his recreational activities to make a double of Madison. The benefits of having two bodies, I suppose. But I felt no differently about the situation than I did when he had first proposed it. I found it highly unethical, an extreme breach of Madison’s privacy and autonomy, and I had every intention of avoiding this new double.
She only came to me at night, emerging from some secret laboratory of the professor’s like a ghost from a dream. Showering after work, I saw her through the fog of the curtain. The mirage of a dress dropped from her body. When she joined me, stepping beneath the shower spray, her frail blue bra and panties became gradually drenched, gradually transparent. She looked down at herself and touched her fingers to the wet fabric, as if realizing an innocent mistake. Turning her back to me, she suggestively held the shower head pipe with both hands, then looked over her shoulder, expecting me to unhook her bra. Which I will confess I did. I draped it over the shower rod. Then she wiggled her bottom, expecting me to remove her panties. Which I will confess I did. I peeled the wet linen from her skin and draped them next to the bra. But I ended things here. I loofahed her lower back, watched the soap slide between her cheeks, then left her to finish washing herself.
After my shower the next night, I emerged from the bathroom to find her propped on her side atop my bed. Pink cotton panties hugged the knoll of her hip and her breasts rested beneath a thin, half-buttoned crop top. She watched me as I dried off, biting her lip, and when I was done, setting the towel on the arm of a chair, she rolled onto her back, arching her knees in the air, and unbuttoned the rest of her top. She waited for me, and while I confess that I couldn’t kick her out of my room at such a late hour, I rebuffed her every effort that night. We shared an innocent bed, though when I woke, stirred by the dawn light, I was still erect, her hand cupped between my legs as she slept.
On the third night I woke to Madison’s double slipping beneath my sheets. I felt her delicate weight on top of me, felt her mouth against my mouth, and as my body began to react, I felt her slip herself onto my cock, the same enveloping warmth as our first time in the bath.
I didn’t stop her at first; half asleep, my hips rose to meet her. But coming to, I was prepared to do the difficult work of stopping, of savoring one final descent of her body onto mine before pulling away and leaving us both unsated. But over her shoulder, as she took long, luxurious rides along my cock, I saw through the mirror into Madison’s room. The sheet had fallen from one corner, and in the moonlight I could just make out her figure. She stood, one hand holding a bed post for balance. All I could see of Harry were his arms wrapped around her stomach.
As her double sat atop my lap, her pelvis grinding against mine, I watched Madison’s body shudder with each of Harry’s thrusts. I watched her toss her hair. Watched her slightly bend one leg. As Harry’s hand rose to squeeze Madison’s right breast, I reached up and felt the breast of her double. As his hand lowered to reach between her legs, I pressed my thumb to her double’s clit. And when Harry held Madison’s arms behind her back, holding her upper body horizontal as he fucked her from behind, I surrendered entirely. I threw her double back onto the bed, pinned her wrists against the mattress, and drove my cock between her legs with the abandon of a lesser man.
As Madison squeezed her knees together, one slightly over the other, her double wrapped her legs around my waist. As the sounds of Madison’s moans vibrated through our wall, her double arched her back away from the bed. As Madison’s tightly hanging breasts bounced in time with her hips, the breasts of her double quivered like the gently shaken surface of a fair and virgin sea.
The four of us came at once, unwittingly together, and I kissed Madison’s double to keep us both quiet.

***
From that night on, the cork was out of the bottle. I no longer resisted the seductions of a willing woman I found so achingly attractive. I spent my days tending the professor’s new batch of organics, and at night I waited for her to appear in my room. I’d kiss her, whisper “hello, my Maddie”—my infatuation deserved a name—and we made hushed, wild love. Once, despite sucking three of my fingers to mask her moans from Madison, Maddie accidentally kicked a bedside lamp to the floor, her leg having twitched from a sudden shift in the depth of my thrust. We stopped mid-tryst, glanced toward the mirror for signs of a reaction, but, seeing none, she took my fingers back into her mouth, begging me to resume.
While her existence had to remain a secret from Madison, I resented the fact that our affair had to stay hidden while Madison and Harry’s was so excruciatingly public. Instead of retiring to my room in the evening, I sought out discreet corners of the professor’s mansion. I never told Maddie where I’d be, but somehow she always appeared.
In the wine cellar, we squeezed ourselves between two stacks of barrels. In the boathouse, Maddie got on all fours against the bow of the professor’s sailboat. In the greenhouse, hiding amongst the orchids in her floral bralette, Maddie wrapped a honeysuckle vine around her bare waist, threaded it through the straps of her thong, and licked the nectar from the pistil of a flower.
All day in the lab I watched Madison bend over a microscope or nibble on the end of a pen or stand with her hands in the back pockets of her jeans and I longed for dusk, when I could lead her double behind the firewood and strip her naked in the grass.
We were nearly caught in the gym locker room. With Maddie on her back along the length of a bench, we suddenly heard a shower turn on, heard Madison’s soft humming. Maddie and I froze, my cock still deep inside her. The shower turned off—evidently only a quick rinse—and we heard the rustling of a towel. I dared not move, but Maddie, placing a hand over her mouth, began squeezing my still cock. I shook my head at her, put a finger to my lips, but I saw her smile beneath her hand, and she began flexing herself more rapidly around my shaft, began shifting her hips inperceptively slowly. I closed my eyes, struggling to contain myself. I grabbed her ass, threatening to spank her, but of course this was a bluff. I began to respond, flexing my cock inside of her while remaining still, the blood rushing to my pouting tip, which only made Maddie flex harder in turn.
We were startled by a loud metallic slam. Then another. A feminine moan and a masculine grunt, and it became clear that Harry was fucking Madison against a row of lockers.
Maddie looked at me as she moved her hips faster, as she began to slide herself less subtly along my cock. I began moving my hips, as well, pulling back only an inch before pushing deep. I flexed and she tightened, then I pulled back only two inches before pushing deep. Until, unable to pace ourselves, and satisfied that Madison couldn’t hear our dalliances over her own, we pounded against each other, finished quickly, mostly quietly, and snuck away with our armfuls of clothes. We hurried down the hallways and, safely out of earshot, I spanked her as we ran.
One night I listened to the cicadas on the back porch, waiting for Maddie to appear through one of the French doors. Instead, enigmatically, I saw her approach the back steps from the dark at the far end of the lawn. She wore a wreath of green around her head and a flowing white gown. The bottom of the dress bore slits along both legs, while the top, knotted over each shoulder, plunged all the way to her waist. As she moved closer, I could see that the top was a transparent lace.
I met her in the grass, careful to stay beneath the roofline, out of sight from the upstairs windows. I kissed her and, eager to unwrap her gown, tried to lead her by the hand toward the house.
But she shook her head. She kissed me again, undid a few buttons of my shirt, then began leading me across the lawn. I was wary, glancing over my shoulder to see if Madison was standing by her window, but I was also transfixed by the gown. While the bottom wasn’t transparent, the silk hugged her backside and flowed around her hips as she walked, a thigh peeking through the slits with each step. She turned occasionally, walking backwards as she glanced at my exposed chest.
“You like?” Maddie asked, seeing me eye her dress.
“I do,” I said.
She smiled. “Will you undress me in the garden?” She asked.
I couldn’t answer. I knew I should have said no, it was too risky. I should have begged her to please let me just cut some fresh foxgloves and sprinkle them across our bed. But of course how could the answer be anything but yes? I let her lead me to a patch of azaleas beneath a dogwood tree, secluded but still lit faintly by a warm light from the house.
Maddie held her hands behind her and leaned back against the tree. She looked me over, expecting me to unbutton the rest of my shirt. But I was reluctant, still trepidatious about our place in the open. Maddie rolled her eyes. She reached up and, untying the knots on each shoulder, let the top of her dress fall, four wide strands of lace hanging from her waist. She sat amongst the red flowers at my feet and her gown spread out around her as if her topless body rose from the petals of a white tulip.
She looked up at me, waiting for me to undress, and once I did, once I stood naked, she fell back amongst the greenery.
“Undress me,” she said,fingering the fabric around her waist, her breasts pressed between her arms.

***
“Where are you hiding her?” Madison asked in the lab.
I tried not to react, but must have glanced at her with a panicked expression.
“Who?” I asked.
“Your visitor. I saw you with a woman last night.”
I busied myself with the organics, pretending to need a radioscopic sensor from across the room.
“You must have been dreaming, Madison. No visitors for me.”
She pursed her lips and turned back to her own computer screen.
“I definitely saw you,” she muttered to herself after a moment.
I ignored her, but then Madison stood and leaned against my desk.
“Listen,” she said, lowering her voice. “I didn’t know you had a girlfriend, but you don’t have to worry about me, you know, telling her anything.”
I looked up, considering my options. “No?” Is what I settled on.
Madison shrugged. “There’s nothing to tell. It’s not like we did anything.”
“That’s true,” I said.
“Shared a bed for one night,” she said. “Nothing anyone needs to know about.”
“I agree.”
“But!” she shouted, leaning suddenly forward. “I do want to meet her.”
“I don’t think so,” I said.
“What? We’re staying in the same house, it’s creepy if I don’t meet her.”
“Professor’s orders,” I said. “Visitors only allowed if they stay absolutely out of sight. The secret nature of the project, our busy schedule—he doesn’t want any distractions.”
“I wouldn’t worry about the professor,” Madison said, which in hindsight was obviously going to be her response. I changed tacts.
“Well she’s also not here long. A few days, and I don’t know how much free time we’ll have,” I said. “Taking advantage of every moment. You can understand that.”
Madison raised an eyebrow. “I suppose,” she said. She got up to go back to her computer, but as she did she gave my thigh a soft squeeze, letting her fingertips drag across my zipper.

Source: reddit.com/r/eroticliterature/comments/10ssep5/forever_hung_part_9_scifi_slow_burn_all