He found her on the mounting block being fucked by a horse. 

That was about it. There was no preamble to the story in Aaron’s memory, no matter how many times he relived it in his mind, regardless of who he was fucking when he thought about it… all he could remember was the sight of his Aunt Isabelle in the stables spread face down on the rounded surface of padded block she’d claimed was used to help train squires to mount up. Broad as a horse’s back, she lay on it with her ass in the air and hands gripping the raised edges of the block as the huge stallion, the prize of her breeding stock pounded her from behind. 

What was there to possibly say? It was not a thing that could have happened by accident, not with that blissfully blank expression of rapture on her face or the moans that echoed in the emptiness of the building. 

Her beautiful, sacred womanhood was stretched to its limit around the immense girth of the stallion’s cock. The length was too much for any woman, but the horse’s progress of its invasion into his mistress was tracked by the coating of juices that slicked its length, sometimes deeper, sometimes shallower, but every thrust had her writhing in pure pleasure, praise for the animal escaping in wordless cries. The humid air was warm, but he barely noticed as his cock, so painfully strained in his pants was finally freed. 

He had scarcely realised what he had done until her lusty eyes fell upon him, upon his own throbbing erection that he shamelessly and openly stroked in front of her. They widened in shock, her already parted lips trying to form some kind of exclamation beyond the moans. 

He wanted to cry, he might have been, his vision was blurred in a haze of rage and arousal at her betrayal of his uncle, of him. He’d loved her. He loved her and she was doing this. Why should he have to hide? Now, here, in this place with as she continued to be rutted out by the horse, as though Uncle Connor was not enough. Everything he had desired and admired her for was shattered. She was nothing more than a slut, a filthy horse slut. 

He stepped up to her, grasping the back of her head and pulling it back so that her mouth gaped open and shoved his own cock in. There was nothing tender about it, no semblance of his fantasies of her teasing those plump lips along his length and showing him the same loving attention she did Uncle Connor, he simply fucked her sweet little mouth and tight, convulsing throat. 

Her body bucking with the force of the thrusts on either end, she stared up at him with tears leaking from her eyes and mingling with the sweat and he met her gaze with one of his own. This is what she deserved and wanted, even if she did not even have the decency to admit it to herself. Her hands clutched at his forearms, but he ignored their fluttering protests, her increasing moans turning to muffled screams as she tried to convey something to him. But she could not have fought back even if she wanted to, fucked silly by the horse. 

The sleek black stallion, eyes rolling wild and snorting began to buck even harder. Whether it was in response to her screams or as the cause of those screams, Aaron could no longer tell, but he got his answer soon enough as her entire body jerked forward, taking his cock down her throat all the way to the hilt. The wet, liquid sound of the stud releasing its fertile load into her spasming pussy was loud in his ears and he watched his aunt’s face turn from panic to absolute, animalistic pleasure. Her eyes nearly rolled back in her head as the sheer instinct overtook her senses, unthinkingly as though it was the first thing that came naturally to her, she began to suck on his member. It was more than he could take, with only a few more thrusts, his own seed began to fill her mouth and throat in thick spurts before he pulled out to anoint her face with a few jets. Just the way he had always dreamed.

A few minutes passed, stallion sated for now, dismounted and slowly pulled its receding erection out from her thoroughly spent, thoroughly fucked pussy. Its seed, at first only escaping as a dribble now flowed from her in a filthy splatter on the stable floor that made his cock twitch. He watched the stallion nuzzle his aunt’s back, a familiar and practiced motion before it backed into its stall like a well trained beast.  

For her part, she could no longer respond, lying prone on the mounting block, covered on both ends in semen. Every breath came as a soft moan, too fucked senseless to even shield herself as Aaron walked around her to inspect the horse’s handiwork. Her entrance was still slightly gaping, enough for him to see the spunk that dripped from the inner recesses, twitching every so often as a particularly thick trickle slid across her swollen clit. 

On impulse, he slid a finger into the mess, exploring the ridges of her entrance and then the slick inner walls beyond. He could feel the smooth muscle of her cervix twitching against his touch, still dipping into the pool of horse cum she had taken like a dirty mare in heat. She was still moaning, her twitching cunt trying to tighten around his finger. So greedy… a horse slut. Unthinkingly he slapped her rounded ass, hard, and felt her tense magnificently, the action squeezing another surge of cum from her pussy. 

The anger wouldn’t drain away, not even after striking her, watching her dripping entrance do the begging that she was too addled to do. It still wanted cock, she still wanted cock. He would give it to her… he stuck another finger into her pussy, scooping out the sticky white fluid and rubbed it into the crack of that gorgeous ass. With the sounds of her beastial encounter still ringing in his ears, he was deaf to any objections, only the sound she made when he spread her ass cheeks and pushed his erection into her back entrance. It was the work of a moment to force the swollen head past her tight little hole, the rest of him following smoothly in a mix of horse cum and her spit. 

Gods, he’d wanted this, all those girls he had played, her daughter Rina, none of them could compare. All this time, since that fated day in the loft, his only real fantasy was her. He fucked her spasming asshole, heedless of how rough he was tearing into her, heedless of how she was screaming. It was a dream and a nightmare, he wanted to banish the memory of the last half an hour, the memory of her fucking the horse and yet the sight of her splayed for the animal was making him throb harder. 

Horse slut, he called her, whispering into her ear like a litany as he pounded into her. His balls slapped against the sticky entrance of her cunt, teasing her swollen clit. Blind to everything but his pleasure, he could only barely register her cries were not… in protest. She was squeezing tight around him, cumming from being fucked in the ass, from being fucked by him. Holding back was impossible, he didn’t want to anyway, burying himself to the hilt in her bowels and releasing his own load. She milked every last spurt from him, his balls straining for one last shot before he collapsed atop her. 

She stank of sweat and horse… and him… her raven hair damp and lank as it clung to her back and shoulders. There wasn’t even a squeak out of her, only a soft pop when he regained the strength to step away and withdraw. The cum leaked from her ass, merely a trickle that was soon lost in the sticky froth of her first tryst and a beaten look in her black eyes as she watched him dress. 

He wouldn’t deliver anything as crude as blackmail, nothing so stupid as that. He was done. He wanted to hate her for ruining him, for destroying his dream. The forbidden pleasure he had longed for was sated in a moment of raw anger and lust, not the fantasy he had treasured these past few years. And yet… 

Even in the dead of night, hours and days from that fateful encounter, alone in his bed and in the dark, his hand working his cock feverishly, he could still see her in his mind’s eye. The feel of her mouth, her ass… he thought of that twitching cunt, this time clinging around him. He had to… one more time…