Diving Towards Perversion

This change in me is a bit embarrassing to talk about, but I have to be a good dog girl and tell my master all about it.

Up to this point, my thoughts had mostly avoided becoming too improper. I had, at worst, imagined you petting my belly and calling me a good girl. I would not let myself fall into depravity, I would just be a normal petgirl sister who cares about her older brother and maybe wants to cuddle with him a bit.

After your acceptance of who I was, I fell, and I fell hard. The night after you held me and told me it would be okay, I had a much different dream than the night before. I do not remember the dream being coherent, but what I do remember was you using my body as a master should, having me submit to your whims and desires, filling every hole in my body with as much cum as you could. I woke up covered in sweat, and more horny than I had ever been in my life.

I pulled out my laptop and opened up petpornhub. During my time trying to convince myself I wasn't a pet, I only watched porn videos with people that looked nothing like you, and I made sure the porn never involved petgirls. I didn't get off much during those months... But I didn't have to hide from the truth anymore.

It took only a moment to find the type of video I was looking for. I started playing with myself as soon as the video began. The pleasure coursed through my body as I imagined you being the step-brother in the video, and me as the petgirl on her knees in front of you. I was so pent up, it took less than 30 seconds before I came hard. My entire body convulsed as I did my best to not let you hear me through our thin walls.

I laid back against my pillow and panted as I felt the euphoria flow in my post-orgasmic bliss. Slowly, as the pleasure faded, I began to feel guilt. I just masturbated to my older brother! I just masturbated to you! What is wrong with me?! Why would I think about my own flesh and blood that way? There was no excuse, there was no absolution awaiting me after this. I wanted you, and I wanted you bad. Yet, I could never have you. **** was illegal, and you'd be ostracized forever. I couldn't do that to you. I had to bottle it up, I had to make sure you never found out.

...I couldn't stop. I'm sorry, big bro. You deserved better, but instead you got a little sister who spent every day for the next month stripping off her pants the moment you walked out the door. The idea of you using my body to get yourself off was tantalizing in a way I could have never imagined. I thought about you putting your hands on my shoulders, pushing me gently down to my knees, fishing out your cock, and telling me to get to work. Other times, I imagined you throwing me onto my bed, telling me to hike my butt up into the air, and then fucking me doggy-style until you came inside me. After all, petgirls are sterile, you could cum inside your little sister whenever you wanted without any consequences whatsoever.

Most of the time, though, I thought of something much more gentle and sweet. I imagined you walking up to me, wrapping your arms around my waist and whispering into my ear, "I love you, my pet." You would walk me over to your bed, kiss me on the forehead, lay me down, and then get on top of me. You would tell me how you wanted my first time to be wonderful, and you would do your best to make me feel as special as I deserved. I had been subconsciously saving myself for you, after all! We would kiss for a short eternity as I told you how you were both the best brother and the best master I could ever ask for. Eventually, when you knew I was ready, you would take off both of our clothes, and we would make love for the first time. Those were my absolute favorite fantasies, the ones where you loved me back as much as I loved you.