Lily looked down at the turgid pole of beastly meat stretching toward her. As it pulsed and grew harder and longer in a matter of moments it was just below her chin. It wobbled with each pulse of her heart, her blood pumping into her lower half, filling Champ's cock with her blood. It was so fucked up.
She saw the tube of meat resting gently in-between her breasts as it felt hot against her chest. It was a bizarre mixture of pleasure and pain. It felt good to have this thing between her legs, but it felt wrong, still. It also was so hard it hurt. Lily had actually had Champ bred regularly. Champ was a phenomenal specimen and was highly desired by many horse-owners to breed their mares.
Lily grimaced at the thought of the potential of having to deal with Champ's previous urges. As she saw the throbbing column in front of her her mind briefly went to her boyfriend, Casey. A tear ran down her cheek as she worried about how he would see her now. He was understanding, but this would be a true test of their relationship. Part of her wanted to ask the doctor to let her call him. Her phone would normally be in her front pocket of her jeans, but she had no idea if the doctor even had her jeans, let alone her legs still nearby.
The desire to contact her boyfriend though took a quick second-place in her mind as she felt the tip of her cock nudge her chin. The head had flared greatly and the trumpet shape was nearly twice the width of her mouth. Instinctively she reached down and began to tenderly lick the cock head beneath her. She reached with one hand to steady the middle of the length, right around the medial ring. Her tongue worked over the large nodules surrounding the tip of her cock. Champ's cock. No. Hers.
In the back of her mind she was disgusted. She had never even thought about being intimate with a horse. Much less her own horse. Though it was herself, now, right? Her tongue danced over the raised, tube-like urethra that extended from the center of her cock head. She felt a tingle as her heart began to race. She felt her balls tighten and flex over and over. She reached down with her other hand and began to rub her testicles. Not content, she began to rub harder and harder. Her grip around her cock also tightened. She was treating herself rougher than she had ever treated Casey. It seemed she needed to be rough to get any satisfaction from her massive, beastly cock. Her package was leathery and thick. Much more durable than the average human penis.
The doctor took diligent notes and made sure his camera was recording as Lily had her instincts take over to reach release.
Lily's rough treatment of her cock was clearly having an effect. Her breathing had been steadily speeding up. Her face had gone red a minute ago. Her licking had also evolved to taking soft bites at the head of her cock, nibbling it's ridge and sucking on the center. Her tail began to swish behind her involuntarily as one of her hoof began to stomp over and over on the floor.
The doctor looked down, slightly concerned that she would crack his floor. She likely didn't realize her own strength with her new lower half.
The loud clacking of her hoof on the floor nearly overpowered the sound of her own moans and gasps. The tight grip around her shaft began to move up and down. The hand on her balls began to grip the top of her sack, above the testicles as she tightened her grip there as well. She pulled her balls hard as her other hand moved up and down nearly in a blur.
Lily was too busy in her current state to notice the doctor had stopped taking notes and was rubbing his erection through his pants.
A few seconds later and Lily's hoof was stomping the floor harder than ever. She began to tense harder as she leaned more forward, trying to cram as much of her oversized shaft into her mouth as possible. Her shaft flexed and swelled as jet after jet of horse cum shot up her shaft and into her mouth. After the third jet her cheeks ballooned and after the fourth she pulled her head up, lips holding tightly. The next and last two jets of cum rocketed out and hit the ceiling above her.
As cum dripped from the ceiling the doctor regained his composure and took back to his notes to finish his observation.
"Wonderful. A complete success.", the doctor said proudly.
Lily spit her mouthful of cum on the floor beside the table she was on. "Oh my god. It tastes so bad...". Her face did nothing to hide her disgust.
"Eh, you'll probably get used to it.", the doctor said, shrugging. "Anyway, you'll be good to be discharged tomorrow morning. I can't in good conscience send you home while this storm is still going on. You can make yourself at home, and let me know if you need anything at all.", the doctor said with a smile.