I still remember my first time with the woman who was mainly responsible for turning me into a slut. My sister, Heather, and I would often spend the weekend over at a friend's house though Heather stayed over there much more often than I did. I found out why and I was shocked when I did.

It was Friday evening and Amber's, our friend, mom and dad worked night shift usually which left us alone on Fridays. Usually we would talk about boys and college and stuff or order pizza and watch a movie. This movie was much more different than usual, it turned out to be a lesbian porno.

I sat on the couch unable to take my eyes off of the screen as there was two women holding another down, fondling her breasts while a fourth was pounding in and out of her at a furious pace with a strap-on. The woman was screaming in pleasure as her whole body shook from the force of the strap-on being thrusted into her.

While I was watching this one of my hands found its way under my night shirt to rub my slit as I grew very wet. I soon had a personal show as Heather and Amber started removing each other's clothing and fondled and kissed each other on the floor by the television. I didn't know what to do, I was growing so hot.

I was so into it I almost didn't notice the basement door open but I did and Amber's mom came walking into the room with a bathrobe on though there was something poking it where a cock would normally be on a guy. I was scared that we were going to get in trouble when Amber's mom just fell down onto the couch and pulled me roughly onto her lap.

"Don't worry, Liz, I know what they do." Amber's mom whispered into my ear. I could feel the long shaft rubbing against me between my legs. She pulled my night shirt up and ran her hands under it and cupped my large tits and squeezed them, "And I know what you want, you little slut."

"I don't want anything." I whimpered as I struggled against her but she pulled me back farther onto her lap and continued to play with my tits.

"Yes you do, you want to be used like the slut you are." Amber's mom said, "You know, I always wanted to touch your tits…they're so perfect. They're even bigger than mine."

"No they aren't." I protested trying to get up again but she wouldn't let me.

"Shhh." Amber's mom whispered, "I have a good show to show you."

"What?" I whimpered, as she pinched my nipples hard, rolling them between her thumb and index finger causing them to grow harder.

"Amber, get Sampson for the little bitch over there." Amber's mom said, "She still hasn't been punished for last week."

Sampson? Their Doberman? I watched as my sister got on her hands and knees with her ass in the air.

"I'm sorry, Mistress." Heather whimpered, "I'll be good."

"You are damned right you will be, you want to act like a bitch you will be ridden like one."

I watched in sick fascination as Amber came back with the large dog and let it sniff Heather's pussy causing her to fidget some.

"Please, Mistress." Heather moaned as the dog started licking her pussy furiously.

"You see, this is your sister's first time with a dog." Amber's mom whispered, moving one of her hands down into my panties as she rubbed my slit causing me to shudder with a moan.

"Up." Amber said, the dog listening as it jumped up to wrap its paws around Heather's waist and started humping her. I watched as Amber guided the growing red shaft into my sister's pussy as it impaled her and shoved her forward hard bringing a scream from her lips. The dog didn't care though, it started pumping in and out of her furiously, the strength and speed of the thrusts too much for heather as she lost her balance and fell forward with her ass in the air where held her with it's paws as it pounded away oblivious to Heather's screams.

I tried to get up to help her but Amber's mom held me firmly as I watched my sister try to brace herself with her elbows, her whole body brutally being bounced back and forth on the dog's cock, her hair flying wildly as her tits swayed back and forth as my sister screamed, shaking her head as she thrashed against the bestial onslaught.

"Make sure they tie." Amber's mom said as Amber reached under my sister and behind the dog pushing them together even more which is when my sister's screams really started in earnest. I know my sister was Cumming over and over but she was also screaming in pain.

"Get it off!" Heather screamed, "Get it off!!"

I started to try and get up again ad to my surprise Amber's mom let me. When I got to my feet though she tripped me and when I landed on my hands and knees she was behind me pulling my shirt up and tearing my panties off.

"What are you doing?" I asked, a little scared.

"Little sluts should listen or be punished." Amber's mom said as she pulled back her robe to show that she was wearing a large strap on. I started to scramble away but she grabbed my hips and pulled me back and shoved that large toy cock in my pussy hard causing my scream to join my sister's. She grabbed a handful of my hair and yanked back on it hard as she started pounding me. I cried out as she invaded my virgin pussy, tearing my hymen and continued to thrust harder and harder, smacking my ass again and again as she laughed.

I fell forward when she let go of my hair as she bent over me, one hand reaching under to smack one of my tits hard as she continued thrusting into me. I screamed as she pounded me for god knows how long, yanking me back onto my hands when I fell over or after she got done abusing my tits. I don't know how many times I orgasmed but when she finally stopped and let me fall to the floor I noticed Heather was but to but with the dog, stuck together. Every time the dog pulled a little or moved caused my sister to cry out.

"Mom, let's bring King in." Amber said.

King, there German Shepard. I started to get up despite the pain but Amber's mom pulled me over to the coffee table as Amber went and brought in the other dog and a couple leashes and rope. Amber's mom forced me down to my knees in front of the skinny part of the coffee table as Amber took one of the leashes and tied my knee to it. Amber's mother took the other leash and did the same to my other knee while I tried to struggle

"Don't struggle you little bitch." Amber's mom growled while bushing me down on the table. She took one piece of rope and ran it under the table and tied each end to one of my wrist so they couldn't reach each other on top of the table. Amber then took the other piece and tied it to my wrist above the table so as far as I could move my wrist was the edge of the table.

I was trapped helpless over the table as Amber's mom smacked my ass. I looked over to see my sister resting her head on he forearms while the dog fidgeted, still stuck to her.

"Up King." Amber's mom commanded. I felt a large weight on my back and the dog's sharp cock stabbing at me and missing. He was having a hard time getting it in but he finally managed bringing a scream from me. While the table kept me from moving much it didn't keep me from feeling the shock from each painful, furious stab bringing scream after scream from me.

Amber pulled me head up by a handful of hair and smacked my tits around as I screamed. She pulled on my nipples as I struggled to keep my head up, the hard pounding making it hard to do so.

"Ride her!" Amber's mom laughed, "Fuck her good king, make her your bitch!"

I could feel something huge growing and smacking against my pussy lips which I was sure was his knot. I screamed louder as I lay helpless over the table being forced to let this dog have his way with me. I felt the warmth of his cumm as he exploded into me filling me up with his cum.

"He didn't get it in mom." Amber said as the dog pulled away from me. I just laid there on the table, both from exhaustion and pain. I looked over to my sister and noticed she was also on the floor, Sampson must have finished with her.

"Well, how does my little bitches feel?" Amber's mom asked.

Was this my last time over there, no way. As the pain slowly faded I also felt so exhilarated and wonderful. I wanted to be filled again like that but not by the dog, I could barely handle him without getting tied. I don't think I would have made it if he got his knot in me.

The next weekend Heather and I stayed over again but this time I found out Amber's father was also in it. He refused to let the dogs have me and took me down to the basement where a few of is friends were. Over the next few hours I was used in about every position imaginable as well as forced to suck several cocks which was the only time condoms wasn't used.

I could have stopped and not went back though but it was too late, I had become a slut. I loved the feeling of cock thrusting in me, I didn't care where it came from. I became a sex toy along with my sister and though Amber and her family moved away I still remain a cum slut as well as my sister. We love it when we can get our college professors to give us extra credit assignments at their homes but all of that is another story.