"Delilah," Taylor whispered, biting her lip.
"Yes, mistress?" the mare answered. Her body rippled, clearly the more powerful of the two, but still willing to address Taylor with her title, if a little mockingly.
"Could I... touch your muscles?
Delilah shrugged. "My body is yours to use," she replied, and leaned back on her arms, basking in the hugeness of her body, and how tight, feminine and strong it felt. Her head tilted back, and she closed her eyes as Taylor stepped close to her.
She started at the feet. Despite her changes, her hooves had remained, with thick, digitigrade legs. At the moment, as she lay with her legs spread, the muscles weren't even flexed, but they still were almost as wide as Taylor's already athletic torso. With a pop, the jar of horse semen was undone. Taylor dipped her hands in, and began to work.
She spread the seed slowly, lavishing every muscle as she dragged her hands across it, leaving a snail trail of white fluid in her path. She rubbed down her calves, feeling as Delilah clenched them in response and ballooned the muscle up to incredible sizes. Up to the thighs, Taylor took great pleasure in rubbing every part of herself over the thick tree trunks. She stared into Delilah's eyes as she sat just shy of her entrance, feeling up the tight muscle that could crush her in seconds. Delilah licked her lips and Taylor let her hands wander over the curvature of her hips, but never too close to her succulent horse cunt. That would come later.
Now crawling along the huge horse anthro, Taylor continued to spread the tainted cum across her huge brick wall of abdominals, and found Delilah could bounce her entire body weight with a few flexes of the cinderblock-sized muscles. Her breasts were given ample attention too - a heavy lathering of cum over the stretched, tight skin. The globes of flesh didn't feel real, too firm and perky and perfect, but Taylor knew they were. She gave a tug on the nipples, sighing in satisfaction as a moan of delight rang out.
Delilah's back wasn't spared, either. Her butt, two cheeks of pure power, was carefully grabbed and fondled, fingers rimming her puffy anus. Farther upward, each pitted muscle was kissed and slathered with seed, rising up to her mountainous shoulders and down her arms. Each bicep threatened to burst as Delilah flexed them to their full oil-drum size, and Taylor could feel each sinew and vein that ran across it beneath her wandering hands. Her forearms, while not quite as impressive, were still thick and swollen, as were her humanoid hands tipped with claws from the latent keratin that remained from her hooves.
After what had been an age of muscle worship, Taylor crept up past her thick neck and began covering her face with cum and kisses. Hands ran through her silky black mane and stroked down her muzzle. Their tongues met in a dance as Taylor kissed Delilah deeply, and offered her another taste of that sweet, musky horse spunk, something the mare greedily accepted. Her black fur was painted white when Taylor's hands finally left her, panting and wet with arousal. Her face was the most lavished of all.
But the cum began to fade away quickly. Taylor watched in depraved delight as every ounce of the cum she slathered onto her mare began to be absorbed, sinking in through her skin, permeating her pores. Delilah, too, could feel the change occurring as every molecule of her being seemed electrified. And Taylor had only half-emptied the jar. All of that cum from her fur and the spoonful she'd swallowed made her muscles pulse and vibrate.
Soon, she gave a yell as the changes began...