Caring for Carrie

It was my parents 25th wedding anniversary. They were going out of town for the weekend. Not a big deal except my younger sister Carrie, 16 is nonverbal special needs. She has the mind of a five year old.
I'm the oldest. I'm John and I'm 18.
Carrie can dress herself if clothes are laid out. She has accidents in her panties sometimes. She follows simple instructions. She has a killer body though. Big tits, small waist, an ass for days. My parents keep her hair short because she hates to wash it.
After list after list and reassuring my parents that I would take good care of Carrie they finally left.
Carrie stood in the door waving bye for five solid minutes.
I expected Carrie to watch her cartoons and play with her stuffed animals. This was not what was happening.
Everywhere I went Carrie followed. In the kitchen, in the living room, outside, I stopped her from following me into the bathroom.
"No. Carrie". I lectured. She pouted and began to cry.
"Ok. Ok. Fine ". I blurted out. "I will leave the door open. But you don't come in. I gotta pee".
I walked into the bathroom. I turned my back to her so she couldn't watch me pull my cock out and pee.
Of course this caused me to have stage fright. You know, when you got to pee but can't. I stood there holding my soft cock and watching Carrie in the mirror.
I close my eyes to envision warm water falls. Hoping that I could pee.
"Yes" I feel myself peeing. I jerk because I feel Carrie touching my arm, then she grabbed my cock.
I jerk and yell. I am still peeing so it's going on the floor. Carrie is still trying to grab my cock.
Finally I manage to get her away from me by pinning her against the counter.
She is steadily staring at my semihard cock.
I am flabbergasted. "Carrie! No. You can't touch" I yell at her.
She reaches out to touch my cock again.
I'm looking at my pee on the wall, the toilet, the rug and the tub.
She grabs my cock. I can't pull back because she has a tight grip.
I decide on a split second to just let her look at it. Hoping she will lose interest in it. So I stand there with my hands on my hips. Posing like Superman while Carrie grabs my cock and moves it around like a joy stick.
I realize my cock is getting harder. The harder it gets the more she touches, grips, rubs and tugs on it. I'm thinking that this is not going to ever end. I move my hand to hers and try to move her hands off my cock.
It's not working. She then moves one hand to her shorts and pulls them out to look at her self.
I am talking to her telling her "Carrie, no. I'm a boy, you're a girl. We are different ".
She is not letting my cock go. My cock is still hard. So I try something else.
I pull her closer and push my hand down her shorts. I feel a lot of hair. I'm actually shocked at her pussy hair. I had never thought about her sexual before. She's always been my retarded sister.
I pushed my fingers into her pussy hair and was shocked again that she was wet. She was very wet actually.
She was turned on! I thought to myself.
I decided that I had to get out of my pee soaked clothes. So I pulled my hands free and pulled my shirt off and pushed my shorts down and stepped out of them.
Carrie released her grip on my hard cock and pushed her shorts off. It was then that I saw her very hair pussy. She pulled her shirt off next. Her huge puffy nipples were hard as the cool air hit them.
Her tits swayed side to side as Carrie reached for my cock again.
I told off running out of the bathroom and Carrie gave pursuit. She was laughing and grabbing at my still hard cock.
I tripped over one of her toys. I landed on her bed. Buttnaked. My cock bobbing freely. Carrie pounced on me. She straddled my legs. Grabbing my cock again.
I laid there breathless while she rubbed and tugged my hard cock.
I decided to let her get her curiosity out.
She pulled and tugged my cock. She rolled the head between her fingers.
I closed my eyes trying to imagine anyone else besides my special needs sister was playing with my cock.
I felt her shift her weight on my legs. I opened my eyes and she was parting her hairy pussy lips. Her tits were swaying and my cock began to twitch.
She grabbed my cock tighter. I felt my precum dripping down my shaft. I was really enjoying her touch.
I began to relax as I watched her.
I slowly moved my hand to her nipple. I squeezed it and rolled it between my fingertips. She smiled.
"Oh you like that Carrie?" I asked. She smiled and grabbed my other hand and placed it on her other nipple.
"Oh you do like it huh?" I whispered again. I inhaled sharply as she grabbed the head of my cock smearing my precum down my shaft.
I squeezed her nipples. Then I massaged her whole tit. I could feel her heat from her hairy pussy.
I moved one hand from her heavy tit down to her pussy. She looked at me and smiled. I slipped one finger into her hairy mound. Her wetness made the parting of her lips easy.
I rubbed my finger across her already hard clit.
"Yeah Carrie that feels good huh"? I whispered.
She smiled and kept her hand on my cock. My other hand started pinching her nipple again. Just as I slipped my finger into her pussy. I felt for her hymen. I slowly moved my finger deeper till I felt resistance.
I squeezed her nipple hard as I pushed my finger through her hymen. She jumped slightly but that was all the reaction she had.
I moved my finger deeper in her hot, wet pussy. I rubbed her clit with my thumb. She began to moan and rock back and forth. Her grip on my cock was still tight.
I kept working her clit and my finger inside her pussy. I felt her pussy getting wetter. She was close to an orgasm. Her body was tense and covered with goosebumps.
I increased pressure on her clit and on her Gspot. She moaned and fell forward.
"Ahhhh yeah. That felt good didn't it Carrie?" I whispered.
I pulled her tighter to my chest. I twisted her nipple hard causing her to cry out and free her grip on my cock.
I kissed her cheek as I positioned the head of my cock in her wet hairy pussy. I thrust my hips forward causing my cock to disappear inside her.
I moaned, she moaned. Her pussy was the tightest I had ever felt. I got lost. I began to hold her hips and thrust deeper and harder each time.
She began to moan louder and tried to push off me. I rolled her onto the mattress and pinned her down. I bit her nipple as I fucked even harder.
She was crying and it was turning me on. I started to ground my cock into her. Her clit was being smashed by my pelvis. Her pussy began to throb and milk my cock
I could not hold my cum any longer. I cried out releasing her nipple from my teeth.
"Aaaaaaah fuck yeah, oh my God oh my God". I groaned. Realizing what I had just done.
I fucked my retarded sister without a condom. ..... and it felt so fucking good.
I held her as my cock finished throbbing deep in her pussy. I felt my cum gush out as I pulled my cock free.
Carrie laid still. Her tits were red and wet from my biting. Her legs still spread with my cum coating her pussy hair. Her legs still shaking from her orgasm.
I fell back thinking that I'm gonna fuck her all weekend and then make her take a plan B pill to prevent her from having my baby.... for now.
"Oh yes little Carrie. You're gonna be my cum slut and you can't tell a soul. " I whispered.