My first SRU story :) When I get organised to get some SRU links, I'll put them in here.

Warning... Adult themes. Parental discretion is advised... If you are not old enough to know what that means, don't read it.

Hung Like a Horse

by Wolphin

My girlfriend cuddled up to me on the couch and looked at me 
seductively.  Her hand traced up my shirt as she lent forward to 
rest against my shoulder.

"I've got a surprise for you," she whispered.

I wrapped an arm around her waist and pulled her closer, kissing 
her on her head.

"Oh?" I enquired.

She nodded and held up a small bottle before me.  I peered at the 
label.  "Hung Like A Horse Massage Oil" was written in a spidery 
script across the top.  I raised an enquiring eyebrow and looked 
at her.

She giggled.

"I got it from that weird shop," she said.  "You know, run by that 
old guy, something like "Stuff is Us" or that."

"Spells 'R' Us," I corrected.

"Yeah," she said with a smile.  "The old guy said this would 
change your life, you just rub it in and well..."

I blushed and she giggled, her hands teasing my belt open.

"Now," she said with mock dominance.  "Be still."

I lay back on the couch and smiled as she eased my jeans down my 
legs.  Next, my boxers were removed and by the time her hands 
returned I was already beginning to feel familiar stirrings.

I felt the warm oil drop onto my exposed flesh, followed a moment 
later by the soft caress of Cathy's hands.  Slowly she covered my 
member with the strange substance.  It was very smooth oil and 
smelt familiar, almost like a mixture of leather and freshly cut 
hay.  As my manhood grew to full attention I felt a pleasurable 
warm sensation spreading out from my groin.

I let out a soft groan.  I felt so big!

Just as that thought flashed through my mind I head Cathy gasp.  
Opening my eyes I looked up questioningly.  Her eyes met mine and 
then descended downwards.  I lifted my head, followed her gaze and 
let out a gasp of my own.

My manhood was huge!

It was easily double its normal length and even as I watched it 
grew longer and thicker.  I was about to say something when Cathy 
beat me to it.

"Argh," she whimpered.  "My fingers."

I looked down at her hands, still wrapped around my shaft and 
noticed it was hard to see where each finger actually was.  They 
all seemed to be flowing into each other.  Curious I eased myself 
from under her and sat up, my now gigantic maleness waving about 
in front of me.  She looked at me and let out another whimper as 
light brown hair began to sprout from her hands and up her arms.

I was going to say something, but suddenly became aware of an 
unusual weight in my groin.  I looked down in time to see my 
ballsac ballooning out between my legs.  It was very uncomfortable 
and I found myself squirming to accommodate it.  Then I noticed 
the brown hair beginning to travel out from my groin, growing down 
my legs and up my chest.  A sharp pain at the base of my spine 
caused me to almost jump to my feet and I peered over my shoulder 
to see what could only be described as a tail protruding from 
above my buttocks.

I looked back at Cathy who was, by now, staring at two hooves on 
the end of rapidly changing human arms.  The hair and the change 
reached her shoulders and I watched in mute fascination as her 
neck extended forwards.  Her head almost looked like it melted, 
dragging her nose and mouth down.  Her eyes moved to the side of 
her now massive head, her pupils grew large and dark, but her 
whites still showed as she let out a whinny of terror.

A pain in my waist switched my attention back to myself and I 
suddenly found myself unable to stand.  For a moment, my balance 
failed and I pitched forward, landing on rapidly solidifying 
fingers.  Looking back between my arms, which were rapidly 
becoming legs, I watched my back legs extend.  I could feel the 
sensations, but I was somehow distant from the event.  I felt my 
feet reforming even as my head pushed out in a similar shape to 
the now equine Cathy.

My vision blurred, but a keener sense of hearing and smell 
compensated for it.  As my mane sprouted and ran up the back of my 
neck I shook my head and let out a nicker.  It was answered by a 
mare standing very close to me.  I leant over and nuzzled along 
her neck, there was a vague memory of a human female, but it faded 
quickly.

The stallion wickered at the mare and leant to sample her juices.  
Hormones from his newly formed testicles raged through his system 
and both creatures succumbed to natural instincts before battering 
a way outside to graze at the roses.

              -+-+-+-+-+-+-+-+-+-+-+-+-+-+-

The old man smiled as he listened to the radio while the customer 
browsed.  The announcer was talking about the strange appearance 
of two horses in the inner city area that afternoon which were 
driving city officials insane as they tried to catch them.  They 
hoped to corner the animals in a local park before rush hour.

The young woman approached the counter with two small vials and 
held them out.  

"Could you help me," she said.  "I'm not sure which I should get."

The man looked down at the labels.  One read, "Sing Like A Bird" 
while the other was "Howl Like A Wolf."  He smiled.

"Well Madam," he said.  "Both are equally effective and both are 
guaranteed to add that little bit of spice."

"Hmmm," she mumbled.  "I'm not sure, I don't really think either 
of them suit who I have in mind."

The man nodded sagely.

"Well then," he said.  "If I could be so bold to perhaps suggest 
the "Growl Like a Tiger" bottle?"

She looked down at the small vial of brown liquid.  

"Oh yes," she said.  "That does sound interesting."

The sale completed, the old man propped himself back up on his 
stool and made a mental note to recommend some good wildlife 
keepers to the mayor the next time they met...