By the time Megan knocked on my door my roommate had left for the weekend. My horse cock was throbbing, though I didn't know how much Megan would be physically capable of. As soon as the door was closed and locked, Megan let her dress fall to the floor, with nothing underneath. She clearly wasn't interested in waiting to fool around.
The first thing I noticed was her hair was longer, and seemed wilder. My eyes traced her back down to her ass, where I was shocked to see...a horse tail? It seemed to be coming from her tailbone, not something she was wearing. She stood there, letting me walk around her to take in the sight her body. Her breasts had grown. Her stomach and legs were firm. She looked in better shape than she had yesterday. But most importantly was her crotch. I stared at what I could only imagine was a horse's cunt. My erection somehow grew bigger, visible stretching my shorts.
"How?" I asked.
---
Yesterday...
"Remember how you gave Bill that experimental PED derived from horse testosterone?" Megan said into her phone.
Oh I think it's working out quite well for him. And as of today I can tell you what happens when you double the dose.
Well, he did anyway.
Guess what part of him changed the most?
Of course I did, but now I'm really sore. I haven't been this sore since I lost my virginity.
Of course I want him to do it again. That was the best sex of my life!
No, I'm not calling to brag. I need your help. Please let me you've got a similar drug based on horse estrogen.
I don't care of it's untested. I need a double dose as soon as possible; I'm seeing him again tomorrow.
Would it work faster if he left a lot of his altered DNA in me?
Don't kink shame me. You would have done the same thing.
Of course I'm on birth control.
I don't care if it's reversible. Trust me: it's worth it!