Accidentally Impregnating Sister

**All sexually active characters in this story are 18+**

"Look at your son," my sister says, holding our newborn child in her arms. Her face radiates motherly love but she's understandably stressed. "You're a father but he can never know."

Our son Malcolm was born today, July 24th. Do I call him my son or my nephew? I guess it doesn't matter. Today he's my son but for the rest of his life, he will be my nephew. Nobody can know what we did. I thank God that he is a healthy boy with no birth defects. He was born with a full head of hair and his eyes are full of wonder. My sister looks beautiful and exhausted holding our son. Her blonde hair is messy and oily. Her skin is glowing and her smile is real. I walk over and caress my son's head. "This is our boy, Colleen," I say with pride. "We made him together."

"Isn't he just beautiful?" my sister says rhetorically and gently kisses Malcolm's head.

I understand why I can't claim to be the boy's father. I understand that could tear our family apart and ruin my son's life. It doesn't make the reality hurt any less. My seed is alive and on this earth and he will never know me to be his father. I will do all I can to be the best uncle I can be. My sister faces the biggest hurdles in this situation. She got pregnant with a "mystery baby" so my parents think she's a whore. She couldn't name the father and had some make up an excuse about her sleeping with so many guys. Her relatively wholesome image was stained because I couldn't pull out. It was only one night... and the next night...and the next few months.

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Spencer has thrown the greatest Halloween parties since I've known him. He's a typical trust fund baby with absent parents. His dad is off on business trips sleeping with mistresses and his mom is rarely home. Spencer is a good guy regardless of his upbringing. He'd never do anyone wrong and he'd give you the shirt off of his back. He paid for a lot of poor kids' sports gear and helped many students buy school supplies. He's been throwing the best parties since I was fourteen. He'd get all the booze you could drink. I thought it would end but now that we're twenty-one he just throws college parties. Booze can be bought legally and the crowd is more diverse.

Tonight is Halloween and Spencer takes it seriously. I think he enjoys giving other people good times and attention because he never got much growing up. Having a rich friend is nice but he's got a good soul in him. His estate is packed with college students from two surrounding universities. He lets me make a profit from the big parties and charge everyone five dollars for entry. If you aren't wearing a orange ribbon on your wrist tonight you'll get escorted out. I bought a large supply of them and me along with four other friends collect the funds and set the ribbons.

Spencer's estate is large and has a huge pool in the back. It's too chilly to swim so everyone is inside. A few people have jumped inside on a dare but no one is communing by the pool. The house is spacious enough. Everywhere you stand there is booze within arms reach. We keep our parties free of hard drugs. A little weed is okay but Spencer is adamantly against things like cocaine and heroin. His mother is a functioning cocaine addict so it's a sore spot for him. The house is covered with spooky decorations. There are spiderwebs and skeletons everywhere. There is a witch's cauldron with "smoke" emitting from it. The speaker system is playing only spooky music. He goes all out for the Holidays. During Thanksgiving he has a Friendsgiving because his family is rarely home. I would come but my family would be upset. It's a nice event for people who are without family.

"So how much did you make tonight, Mike?" Spencer asks and sips from his flask. He's wearing a highly detailed Skeletor outfit but his mask is pushed up so he can drink. I'm dressed as Tuxedo Mask because it's simple to pull of. My identity isn't hidden like Spencer's but it's what I threw together.

"Like a thousand," I answer and lean against the kitchen counter. "Give or take."

"Nice, another successful night for you."

"Please, that'll buy me like one college textbook."

"Progress."

I notice a gorgeous looking woman entering the party through the crowd. Her face is covered but her body looks amazing. She's dressed as a even sluttier Catwoman. She looks like if Catwoman forgot half of her outfit. She is wearing a black leather leotard and a mask with ears. Her mouth and chin are visible and so are her arms. Her legs and the bottom of her ass are visible through fishnet stockings. She has on heeled leather boots that go up to her mid calf. I look at Spencer and he's already looking at me. We have a silent exchange of facial expressions but he raises his hands up in defeat. I make sure my costume is hat is on straight and head towards the sexy woman. As I leave the kitchen and pass through the dining room the music gets louder and louder. It'll be difficult to talk to this girl but I have the ultimate pickup tactic. I'm the one with the ribbons for entry so she has to talk to me. I have a few left just in case some stragglers or beautiful women like her show up. I make my way through the living room and awkwardly shimmy past drunk costumed college kids. I almost trip this woman dressed as sexy female Indiana Jones. People greet me but my goal is to make it to the woman.

I make eye contact with her and wave. I pass through the remaining human obstacles and introduce myself, "I'm Mike, welcome to the party." The music is almost deafening so I'm not entirely sure she heard me. I hold out my hand and she grabs it. Her grip is soft and wholesome. She has the prettiest brown eyes I've ever seen. They look familiar but brown is the most common color in eyes. While still holding my hand she raises her other hand and motions for me to come closer. I lean in and she puts her mouth to my ear.

"Are you the guy I have to pay?" the woman asks softly. Her mouth touching my ear and the feeling of her hand sends an erotic chill down my spine.

"I am the guy," I say back. "But I'll let you in for free. Just don't tell anyone." I reach in my pocket and pull out a ribbon. She look me in the eyes only inches from my face. She has big wide eyes and small lips. I take her hand and begin tying a perfect ribbon on her wrist. I take my time just so I have an excuse to hold her hand. "You're hand is really soft."

The woman leans to my ear and whispers, "thanks, dear."

She looks to be a couple of years younger than me. Her body is delicious in this outfit. If she moved too fast her tits would pop out the top. They look big enough to be a handful. Half of her ass is exposed through the fishnets and I'm not hiding the fact that I'm checking her out. "You go to many parties?" I ask.

"This is my first one... I'm a little shy."

"You're shy? I couldn't tell."

I take her hang and guide her over to the coffee table by the couch. This woman doesn't talk much but she seems interested in me. She nods her head a lot and only talks gently through the loud music. She doesn't want anything heavy so I fill her a plastic cup with beer from a keg. Spencer is across the room talking to two sorority girls at the same time. We make eye contact and he shrugs his shoulders implying that he did better than me. The woman I'm with now is worth two sorority girls in my eyes. I hand her a cup of beer and lean close so she can hear me. "What's your name."

She looks at me nervously and whispers, "uhm,,,Car-Nicole. My name is Nicole."

"Nice to meet you, Nicole, I'm Mike."

"I know."

"You know?"

"Uhm, yeah, you told me when I came in."

"Oh, that's right. I thought you couldn't hear me."

Nicole seems interested in me but I can tell that this isn't her element. She wears the slutty costume well but this isn't her scene. She's sticking beside me like a lost puppy but is hiding her discomfort well. She handles all the eyes on her with grace. My two buddies were sitting on the couch so I point at them and gesture for them to move. They see the woman I'm with and quickly oblige. I take Nicole's hand and sit down on the couch. There are two women naked to us aggressively making out on the couch.

"So how are you enjoying your first party?" I ask and take a sip of beer. Nicole seems more comfortable now that she has a spot to sit down. She takes a sip of beer and makes a face like she's not used to alcohol.

"I was really scared at first," Nicole answers honestly. "But then this really cute guy came to my rescue so now it's better."

"Who is this cute guy? I'd like to meet my competition."

"He's tall and handsome and he's wearing a Tuxedo Mask costume."

Nicole is a natural flirt when she's comfortable. We exchange some witty banter and I try not to talk so much. Guys ruin their chances by telling women with "impressive" stories and anecdotes about themselves. I always give women room to talk and share about themselves. I share my basic information like that my favorite band is Coheed & Cambria and I am a student. Nicole seems wary to tell me anything about herself. She hasn't left my side and we are holding hands on the couch but she's cautious. I ask her to tell me her favorite show and she has to think about it. I ask her where she is from and she thinks for a moment and tells me "out of state." I gather that she is a new college student and that she's unsure of her future. Normally, I'd take the lack of response as a sign of no interest but she is very interested. Her eyes are focused on me and she's comfortable with me. He hasn't let go of my hand. I put my hand on her thigh and she reacts positively. She spreads her legs open a big so I can slide my hand back and forth. She looks down at my hand and nervously bites her lip.

"Mike," she says softly, looking up at me. "I'm sorry if I'm really...cryptic. I'm not usually like this. I'm just at a crowded party and I'm dressed like a whore."

I laugh and say, "it's Halloween, the time for being a whore is now."

"My friend said she'd come with me but she bailed on me so now I'm alone at my first party."

"You never went to parties in high school?"

"No, I was on the honor roll."

"Information at last! So you were on the honor roll!"

Nicole seems to be loosening up. I can't shake the feeling that I know this girl but the name escapes me. She's giving me no personal information and mostly nods her head. But I feel like I've met her somewhere. Her body reminds me of a cheerleader. My sister was on the cheer squad in high school and they were all built like Nicole. She's very witty and quick with responses. She's good at answering a question with a witty answer that doesn't answer the question. I'm not going to pry. I don't expect this to lead to anything serious. If I were dating her this would bother me but she's just a hot chick on Halloween. I'm hoping to get my dick wet tonight. We have a good chemistry and we match each other's wit. Talking to her feels so familiar that it's almost creepy.

"Alright, I'll give you a direct fact about myself," Nicole says. "I have long hair but it's all tucked in a wig cap."

"How long?" I ask.

"Just past my boobs," Nicole answers and places both her hands under her breasts to further explain. We talk more and she's a sweet girl. Maybe after I get laid this can become something more? I decide to make my move and lean in for a kiss. She gives me permission by leaning in as well. Our lips touch and I put my hand on the side of her cheek. What was supposed to be a testing-the-waters starter kiss became a make out session fast. Nicole puts her leg over my leg and I explore her body with my hands. We pull back and she looks hungry for more affection.

"That was fast," I say, out of breath.

"Is that a bad thing?" Nicole asks shamefully.

"No, no, it's a very good thing."

"I don't want to be a fast girl."

"I didn't mean it in that way. I just meant this happened fast."

"I know. I just get so in my head sometimes."

I take her cheek in my hand and kiss her gently. Nicole seems like she was moving fast to appease me. If she wants things to go a little slower, that's fine. I pull back from her lips and kiss her cheek and her neck. I whisper in hear ear, "you're really pretty, Nicole."

Nicole kisses my chin and cheek and whispers back, "you're quite handsome, Mike."

We kiss passionately and gently. She kisses with a lack of experience but I can feel her following my lead. It's cute the way she mimics my techniques on me. I feel her trying to impress me but I'm already impressed. My hands wander down her sides and feel her hips. I'm not sure how much time has passed because we've been in our own little world.

Nicole takes my hand and asks, "would you like to go to a room?"

"Are you sure?" I say, surprised.

"I think so."

"I want you to know so. It won't be good if you don't want it."

"Mike, I want it. God, do I want it."

We get up and walk upstairs while holding hands. Spencer is going into another room with the two sorority girls. He gives me a salute and I give him a nod. I've hooked up with plenty of girls at Spencer's house and I always use the same guest bedroom. I guide Nicole inside and look the door behind us. We sit at the foot of the bed and begin kissing again. All the movement has caused her breasts to pop out of her costume. I run my fingers along her right breast and kiss her passionately. She lies down on her back and I get on top and kiss her. She feels my bulge through my dress pants and grins. "Is this all for me?" Nicole asks sexily.

"No, it's for the woman dressed as Batgirl that's hiding in the bathroom," I answer jokingly.

"Shut up," Nicole giggles.

I hear the sound of something unclasping. Nicole undid the clasp at the bottom of her leotard. I was under the impression that you'd have to take the leotard off like pants but the clasp makes sex easier. I kiss her and slide my hand down her costume. I feel the open clasp and then feel her wet pussy on my hand. It's soaked. The leather in her crotch area is soaked and it feels like she's been wet for a while now. I rub the outside of her pussy and bring the hand up to her mouth. Without me asking she puts my fingers in her mouth and monas. "That was so damn sexy," Nicole says in a voice that is familiar to me. "What the hell."

I kiss her again and bring my hand back down to her pussy. I insert a finger and rub her clit with my thumb. I haven't seen her pussy yet but it feels divine. Her left lip is larger than her right. Her clit is swollen and excited. I kiss down her body and come face to face with her pussy. I turn my head to the side and make out with her pussy like it's a pair of lips and Nicole moans. I straighten my head out and focus my licks on her clit. She pulls my head closer and closes her knees around my head. "FUCK FUCK FUCK!" She says loudly in a eerily familiar voice. I've heard that voice yell those words before. Juices cover my lips and enter my mouth as she cums and spasms. I lick relentlessly until she pushes me away. I crawl back up her body and kiss her on the lips. She has a big smile on her face.

"Do you have condoms?" Nicole responsibly asks.

"I should," I answer. I stand up and check my pockets. Nicole lies there with her legs spread and her wet pussy waiting for me. God, I hope I have condoms. I check my wallet and there are none to be found. I'm sure someone at the party has condoms. "I don't have any but I can ask around."

"NO!" Nicole says loudly, stopping me in my tracks. The louder she talks the more familiar her voice sounds to me. "Sorry, I don't mean to be rude but that's just embarrassing for me. You understand?"

"Oh, no, I get it."

"You can just fuck me."

"Are you on the pill?"

"No."

"So..."

"Just pull out."

"You sure about that?"

"I've never been more sure about anything in my life. All of me wants you to fuck me right now."

I rush out of my pants and boxers and get back on top of Nicole. I cover her face and neck in kisses and prepare my dick for entry. I want to see her eyes as it slides inside of her. I feel the head pressing against the opening. I grab the base of my dick and hold it steady. Every tap against her pussy causes her to moan. I give her a soft kiss and look her in the eyes. Slowly I slide the head inside of her welcoming pussy and her eyes widen. I push further inside and her eyes widen even more. With one big thrust I push myself fully inside and she lets out a loud yelp. Her tits jiggle as I thrust in. I take it slow with a few soft back and forth thrusts.

"I'm not a virgin," Nicole says. "You can fuck me like you mean it."

"I didn't think you were a virgin." I say as I thrust forward.

"Hey, what's that supposed to mean."

"I worded that poorly."

I speed up my thrusts and add more power to my hips. She moves her hips in conjunction with mine and we the feeling is amazing. Her pussy is without a doubt the softest and wettest pussy I've ever felt. I have good stamina but she's so tight and wet that I think I'm going to cum if I don't focus. My dick feels drenched in vaginal fluids. Her legs wrap around me and her hands slide up and down my back.

"Mikey, holy shit, holy shit!" She moans into loudly. Okay, that's it. The familiarity is freaking me out too much. I would let her identity remain a mystery but I can't let this go on. I pull her mask off and am face to face with my eighteen-year old sister Colleen. So many emotions wash over me. I am shocked that innocent Colleen is at a college party. I remember that I am balls deep inside of my sister but it feels too good to pull out. I feel disgusted and bad about myself so I stop moving. My dick is still inside of her and Colleen is reaching for her mask but I am holding it away from her. She gives up and resorts to covering her face with her hands.

"Colleen!" I say angrily. "What the fuck!"

"Mikey, I'm sorry," my sister apologizes. "You were just so nice to me."

"You're my sister!" I say without removing my dick from inside of her.

"Tonight I'm Nicole."

"This isn't funny."

"It feels good, right?"

Colleen starts moving her hips under me causing my dick to slide in and out of her. That feeling of pure pleasure returns to me and it feels better now. The taboo of knowing it's my sister along with the chemistry and how the night has gone only amplifies it. My mind is warped right now but the biggest feeling is pleasure. "Colleen, stop," I protest weakly.

"You don't want me to stop," she says moving her hips around under me. She takes the mask out of my hand and puts it back on her face. "You made me cum earlier so now I want to make you cum. It's only fair."

My whole body feels conflicted. I'm feeling the most pleasure I have ever felt in my life but I'm fucking my sister. I am mentally trying to rationalize and make deals with myself. I've already been fucking her so what's wrong with finishing the job? I'll never do it again. I'll bust a nut and we go back to normal. Can I really live with the knowledge that I know what the inside of my sister's vagina feels like? Will I be able to take this information with me to the grave? This is some Game Of Thrones shit. Without thinking I have started thrusting again and matching my sister's pace.

"Fuck it," I say and start thrusting hard again. I kiss my sister on the lips with full knowledge that she is my sister. This is my first chosen act of incest and I'm loving it. "I think I'm going to cum soon. I usually last way longer."

"It's okay, Mikey," my sister whispers in my ear. "Just cum for me, baby. Cum, cum, cum, I need you to fucking cum."

"Holy shit."

"Just fucking cum. God, I'm going to make my brother cum and that's fucked up. We're so fucking nasty and dirty."

"Colleen..."

"I knew who you were right away. Your costume hides nothing. I saw you and thought that this was my chance to fuck you. Fuck, fuck, fuck. Do you know how long I've wanted to fuck you, Mikey?"