The stallion ran down the street, shocking onlookers, before jumping the fence into the backyard of a large, modern house. The house was owned by Dan's aunt and uncle who frequently traveled, currently it's only occupant was the former Dan's cousin Maya.
Maya was a reclusive girl, she rarely went with her parents on their holidays, insteading choosing to stay home. She was reading in her room when she was startled by the sound of hooves and neighing in the yard, she came downstairs and out the backdoor to be met with the sight of a what used to be Dan, though she had no way of knowing that.
When he was human Dan had had a crush on Maya. As his cousin he was unable to act upon this, but now as a horse, free of human inhibition he had been drawn to her. Needing a release for his straining balls and having already filled Kat earlier, Maya was the next logical mating partner in his now equine mind.
Stunned by the sight of a horse with balls the size of beachballs, Maya had no time to react as the stallion rushed her and proceeded to rip her shirt away with it's large teeth, falling backwards, terrified and unable to act Maya was easy prey, and her shortss and panties soon followed, leaving her naked and exposed to the stallion.
Finally acting, Maya scrambled up and away and tried to run, but she was far too slow to outrun a horse, even one slowed by balls as large as it possessed. Knocking her down Dan proceeded to penetrate her, knocking the breath out of her and beginning to pound away.
As full to bursting as the stallion was the coupling lasted mere seconds before he began to unload into Maya. She moaned as the huge girth within her pulsed and pumped her full of seed. Such a coupling would have killed her normally but the magical seed created from the remnants of her aunt strengthened her body, even as her belly began to expand.
As the pulses continued Maya's belly grew to enormous size, she looked to be pregnant with triplets by the time Dan pulled free, cum oozing from her gaping sex. She moaned, unable to move as the magic infused cum began to change her.