Nothing happened much during the day for Jen. It was just another routine day at school. When the final bell rang she left to climb back on the bus. She found a seat and settled in for the journey home just as Susan climbed on and decided to sit next to her. Before long the bus was moving and dropping kids off.
"How was your day?" Jen asked.
"Oh, nothing special but I did learn that there is a plan for a girls only party in the works."
"Oh? Who's hosting the party?"
"You know Karen?"
"Only by name and news that travels through the grape vine."
"Ok, well it turns out her 18th birthday wasn't too long ago and she wants to do something a bit exciting her final year so she is planning on a party for next weekend and has a few surprises for those that attend."
"That is intriguing. Is it going to be just her close friends?"
"I'm not sure. Well this is my stop I will see you later."
The bus stops and a few kids walk off and Susan gets up and walks off last. Eventually Jen finds her way home and has a stray thought of horses run through her head but was pushed aside by the idea of a party.
The next couple days went by quick for Jen. It was pretty normal although she had thoughts of horses more frequently as each day passed. She didn't think much of it because they didn't lead to much. Jen also found herself looking at some of the hotties in school a little more than usual as well. Being the quiet girl she is she quickly looked away when they looked her way. Even the word of the party was quiet, so quiet in fact that she thought it was just rumor to stir excitement.
The next day came and went again without much fuss. Again she felt a bit more excited than usual for no reason. While at home she couldn't get the idea of horses out of her head. In fact the more she thought about them the more she was turned on and couldn't figure out why. Jen fought the urge by beginning to work on her homework. When she opened her backpack she found a pink paper tucked inside. She looked at it quizzically because she didn't remember putting that in her bag. So she pulled it out and looked at it, and turns out that it was an invitation to Karen's all girl senior party and it was advertising a late nighter. Jen could hardly believe it. The party wasn't just a rumor like she thought and considering that she got an invitation without her knowledge she thought it must be a secretive thing. She was excited and looking forward to it.
Another week had passed and Jen was getting really antsy which seemed to manifest in a variety of ways. She was staring more and more at the hotties while imagining a variety of dirty thoughts at the same time. More peculiar to her was that horses were almost always on her mind and when they were she couldn't concentrate on anything. She thought it was due to her excitement for the party that she drifted so much in thought. The hours dragged on as she waited for Susan to arrive to pick her up to go to the party. When Susan did arrive, Jen grabbed her things and headed out. It was short drive across town and they found themselves at Karen's place.
They got out and walked in and there were quite a few girls there already but still many had yet to arrive. So Susan and Jen mingled with the other girls some talked, while others played games, did each other's hair, and even messaged on their phones. As the night went on and no one else arrived Karen got up and flashed the lights in the room to get the girls attention.
"Alright ladies, time to start the real fun. I know many have speculated what the surprises would be but let me tell you none of you were right. Tonight everyone will leave with something they will never forget." Karen walks out of sight for a short time and comes back holding a box.
"This is a box of fun and we are going to play a little game. So everyone gather round the edge of the room." As Karen gave the instruction the girls started moving about and she walked towards the center. Then she put the box down then got a chair and placed it in front of the box. The girls giggled as they assumed what they were going to play.
"Alright, now this how the game is going to work. We will take turns sitting in this chair. Whoever is in the chair will be blindfolded the box will be opened and the lights will go out. When I say ready go, you will reach in the box and find something to pull out. You will have to do it quickly because as soon as I say stop you will grab the thing pull it out and the lights will be flipped back on. Then you will have the choice to use it right then and keep it or put it back in the box. Any questions?" Karen paused and looked around the room.
"Who wants to go first?" Karen asks. Again another brief pause as the girls looked around the room at each other. Susan then stands and says "well I'm up for a little fun" as she walked over and sat on the chair. Karen put the blindfold on, then walked over to the light switch she paused and then reached up and gave a quick flick of the switch and said "GO!". Susan leaned over quickly placed her hands on the box then found the top flaps pulled them open and began rummaging through the box. Her hand rested on something large when Karen yelled stop and flicked the lights on. Susan then pulled out the large object and everyone gasped at what they saw. Karen smirked and walked over to Susan and said "Are you going to keep it or put it back?" "Whatever it is I'm keeping it." Susan replied. Karen then took off the blind fold and Susan's eyes went wide with shock when she saw what she was holding. It was a 3 foot dildo shaped like a horse cock. "Well since you're going to keep it, you have to follow the rules Susan." Karen stated. "That's huge, there's no way I'm using it nor especially that in front of everyone!" She shouted. Unbeknownst to everyone else, Jen sat there and was fixated on the large horse dildo. It excited her to no end and she had the urge to try it right then and there. As Karen and Susan were bickering Jen stood up walked over and grabbed the cock. They both looked to see who it was. "Sorry but you have to wait your turn Jen." Karen said. "But I can't wait and I want it!" Jen retorted generating a shocked look from everyone. She pulled the dildo away from Susan's grasp then with one hand she pulled her pants down revealing her tight ass. Before she could think her body placed the head of the dildo at her anus and began to press it in. The girls were in utter surprise as they witnessed what was happening before them. Not only was Jen going to use it but she was shoving it up her ass. At first Jen struggled to insert it because her hole just wouldn't give way to the intruder. She continued to apply pressure and then she felt her hole gradually widen and the horse dildo move inward just a hair. Jen didn't let up and pressed harder and soon was rewarded with her efforts as her anus suddenly gave way and the head vanished completely. Jen gasped in shock as she felt the intruder suddenly enter her backside. Everyone couldn't believe that someone just fit that huge thing in an even smaller hole. Jen then placed the other end of the dildo on the floor and began riding the dildo hard and as fast as she could. She was lost in ecstasy the pleasure was intense and she felt all her excitement from the past weeks wash away with each thrust.
For everyone time seemed to have stopped as they watched Jen go to town on the horse cock. Jen didn't care that she was being watched all she wanted to do was ride that cock as she thought of a big stallion fucking her one right after another. Her pleasure just continued to build with no signs of release any time soon. Five minutes passed from her hard thrusting and her legs gave way and she leaned forward and collapsed on the floor as the dildo popped out of her ass. She looked down and saw her legs were stuck together. Jen quickly snapped out of it and could tell something wasn't right because she couldn't control her legs or feel the floor underneath them. Then suddenly she recalled the curse from 2 weeks ago as she lost feeling in her arms as they moved to her side. She looked back at Susan and shouted "Susan help me quick! The curse is real!" Susan looked horrified as Jen looked back and saw her legs were shrinking merging with each other. Not only that her arms were being absorbed into her torso. Despite the sight Jen wasn't in pain but rather felt her pleasure continue to climb. She laid there and was able to roll onto her back as she watched her body lose its form, shrink, and narrow. At this point she realized the curse wasn't specific on whether the horse cock had to be flesh and that she was turning into that exact horse dildo she just fucked. It wasn't long before her breasts began losing their shape, flattening out with the rest of her form. She noticed that her skin now turning into black plastic just like the dildo as she felt her head face widen as she looked upwards. At this point she could feel her climax closing in just as the plastic was reaching her head and she released a loud squeal in pleasure as a little spurt of cum shot out her mouth before the transformation was complete.
The girls were horrified, puzzled, and couldn't quite grasp what just happened. Susan looked at her best friend turned horse cock stunned and overcome with emotion. She then realized the story that Jen told her was true and the curse was real.