The scientists sharing this room with the lovebirds mostly left - save for al-Zawahi herself, who moved over to a nearby computer terminal as Alex and Susie became too lost in each other's transformed bodies to notice her. It was for a practical purpose, of course: the first sexual encounter of a Queen's Stallion needed to be carefully monitored, with constant attention paid to vital readings to ensure that any issues or abnormalities from the retroviral process were caught and corrected now. Such safety procedures were even more critical in the case of Alex, with her extensive battery of cybernetics, not to mention the need to make sure the couple's neural implants didn't fry their brains.
As always, the doctor was a consummate professional, focus firmly on the task at hand... though even she had to admit, deep down, that it was hard to keep from fondling her own chest as she watched their furious lovemaking playout.
Alex had started slowly, gradually increasing the rythym at which she thrust into Susie's mouth. The longer it went on, the faster she rammed and retracted, until she was starting to reach a pace that exceeded any unaltered human being's capability. Driven by powerful servos with extraordinarily precise computerized controls, the long brass rod slid past her plump lips so quickly that it created friction heating. Only a bit of foresight on al-Zawahi's part, in the form of increasing salivia output to provide a natural coolant, was preventing burns from occurring.
Susie's own condierable member was throbbing in turn, hardened to its full length and pumping in between her enormous udders. She couldn't even manage moans at this point - with an engorged hunk of brass occupying her throat constantly, it was all she could manage just to breathe. The constriction only further aroused her, which in turn created a feedback loop, her inability to orgasm making her even more aroused, which made her need to orgasm more intensely, which made her even more aroused... and so on and so forth, an endless cycle that she was certain would end with her literally and physically exploding from pent-up lust.
In the midst of the rapid-fire thrusting, however, she was left in shock by one last, extraordinarily powerful motion, one that sent the full length of her wife's girthy metal cock all the way inside her mouth, thick lips pressing tight against Alex's crotch. A heavily muffled scream of delight could be heard as Susie's eyes rolled back, her whole body quivering from the feeling of the entire shaft deep down her throat. Her golden eyes were practically aglow with lust as she looked up at Alex; the cyborg slowly slid back, taking whole minutes to retract at a microscopic pace and relishing as it continued to leave her wife incredibly short of breath.
The retraction stopped with only the head still inside the dorse's mouth, which didn't stop her from sucking like her life depended on it. With all four robotic hands gripping her shaft, the cyborg shuddered, fighting to hold herself back just to further draw out her wife's shaking state of bound ecstacy. Yet she could only hold back for so long, especially as the artificiant components in her aching sack began to manufacture massive quantities of the sticky, protien-laden fluid her wife would now be dependent upon. The little factories within her oversized balls were producing like mad, and in spite of her best efforts, they could remain backed up for only so long.
She screamed as the first load hurtled down the length of her brass-skinned member, steaming hot and fired as a set of squirting globs that nearly blocked her wife's windpipe. Yet with the considerable suction power she now possessed, Susie was able to swallow it down, tears streaming down her face at the sheer shoy of that delicious, salty goop rushing into her, burning its way down her throat. The release had a secondary effect: it finally met the criteria that allowed Susie to at last explode, muffled cries accompanying a huge spurt from her own equine rod, smacking violently into her wife's metallic legs. Her body was rocking like an earthquake as the most powerful orgasm of her life overtook her, overtook everything, sending her mind into a tailspin.
It didn't stop, continuing on so long as Alex kept the end of her member in Susie's mouth, the constant stream of human-esque cum keeping her in a perpetual explosion of pleasure. Truth be told, Alex could have spent the rest of eternity locked into such a state and been content, but it would be such a waste of two gloriously sexualized bodies. With a great deal of willpower she forced herself to pull out of the dorse's mouth completely, a loud pop accompanying the escape. Susie continued to tremble as the orgasm went on, and Alex moved fast, intent on not letting her wife have even a moment where she wasn't convulsing and moaning in bliss.
With superhuman strength granted by her new servo-driven arms, Alex forced the Queen's Stallion to flip over onto her back, the enormous weight of her enhanced features instantly pinning Susie hopelessly to the ground. She whinnied and moaned as Alex stood over her, straddling the dorse, and slowly lowered herself down. The pair of hands from her back were put to use in grasping Susie's squirting shaft and guiding it up to her own throbbing, rubberized folds; they both cried anew as Alex was penetrated, her pace accelerating so that she could fully slot the lengthly member inside her body. The enormouse pleasure made focusing quite difficult, but she pushed ahead, groaning in delight as her brass shaft shoved its way between her lover's pillowy tits.
The golden nipples were squirting wildly already, spewing milk all over the place, and the streams only picked up in intensity as Susie once again craned her neck to accept the end of her wife's metal cock. She could hardly move, the weight of her own body combined with her wife's strength keeping her locked down, and she adored every second of it. Hooves flailed wildly as she fought in vain to free herself, solely because she knew it would egg her wife on, force Alex to pump harder and faster, and in turn drive her own piece to srapy even more globs of sticky fluid into her wife's cyborg body. Truth be told, Alex was locked in place just as much as Susie - dominantly in place, but still too hopelessly lustful and in love to consider moving away from this spot.
Staminas enhanced by the procedures they'd undergone, Susie and Alex would end up spending hours like this, locked in a cycle of mutual penetration, occasionally shifting around to better explore their new bodies, find new ways to ram into each other. By the time they were finally too exhausted to continue, they were slathered in a mixture of human and horse cum, with plenty of milk adding a further creaminess to the concoction. After so many hours of completely dominating her wife, Alex had retreated away from a purely domineering role - she was instead reminding Susie why she could be trusted, gently holding and caressing her wife as they lay on the floor, figuring out how to make out with Susie's altered facial structure.
"Truly magnificent."
They both looked up to see that al-Zawahi was stil there, albeit with her lab coat and shirt removed, leaving her with nothing more than a white bra - one stained at the nips. The sweat on her brow made it evident that her self-control had been under constant assault during that long session of lovemaking. "I'm proud to say that you two are not only the picture of health - you've been one of the most ideal couples to go through our radical alteration procedures. In fact..." She bit her lip before stepping around the computer terminal, and the wives couldn't help but notice that there was a further small stain on her pants - Susie had gotten wet from just the sight of Alex often enough to recognize that kind of damp spot. "I'd... like to make a little proposal for our new greatest success stories..."