At first she stepped toward the human dick, disgusted by the shape and very idea of sucking the equine phallus, even if it did hold the promise of feeding her far more cum. But then she couldn't shake the thought. More cum. So much more cum.
She hated herself for doing it, but she knelt in front of the enormous horse dong and stroked the spongy shaft. The musk was powerful and made her head swim, shooting through her nostrils straight down to her pussy. She didn't even notice that she was leaning in closer, her eyes shut as she lost herself in the ever heightening pleasure of her depravity, each breathe deeper and closer to the beastly stench until her nose pressed right up against the shaft.
She jolted back. What was she doing? Wasn't it enough that she merely craved its cum? Did she really want to sandwich that gorgeous mottled shaft between her tits and smell its wonderful scent until it spewed its enormous load all over her face and chest?
Fuck yes. She swooped the two-foot club into her cleavage, the wide flat head just below her nose, and she breathed in with the full strength of her lungs. The pheromones, another one of the facilities experiments, finished re-writing her mind and the cumslut started her blowjob in earnest.
She heard a hoof stomp on the floor, and then thick, salty cum flooded her mouth. She swallowed and swallowed, cum dribbling from the sides of her mouth and onto her growing tits. She watched with joy as her nipples lengthened and darkened into black, leathery teats, and sensed that more was about to happen.