Note 1: This is a Halloween 2013 contest story ... I hope you enjoy.

Note 2: Unlike many of my stories, this one is short on detailed character development and more about the sex.

Note 3: Of course, all participants are eighteen or older (in this case just eighteen).

Note 4: Thanks to MAB7991 for his usual editing work and Goamz for a last minute edit check.

When did the plan to fuck my twin sister formulate?

In truth, ninety percent of my stroke fantasies were of my gorgeous, bitch sister; ninety percent of those were revenge fantasies where I made her my little slut. Although I am a nerd and hardly a ladies' man, I have a sinister side. My fantasies range vastly on how I would make her my submissive little slut but they always include fucking her face, filling her cunt and pounding her ass.

By the way, I am not a virgin like in every movie or book about nerds. I got my first hand job on the bus coming back from a school trip (teachers don't check up on the nerds), got my first oral sex, giving and receiving at a debate tournament, and lost my virginity to a girl dressed as Princess Leia at Comic Con when I fucked her ass in her hotel room while her roommate took on two guys (strangely she wouldn't let me fuck her pussy as she was saving herself for marriage). So here I was eighteen, with some sexual experience, but I had never fucked a girl's pussy ... then the perfect opportunity just dropped in my lap.

Wendy's phone rang when she was in the shower. I answered it and her college boyfriend was on the other line.

"Hi," I answered.

"Hey twerp, where's Wendy?" He asked, always treating me like I was his annoying little brother.

"In the shower getting ready for her last high school Halloween party," I replied, the last few words dripping with sarcasm after listening to her and her friend Tara using those exact words.

"Your sis can really be over dramatic," he said.

"No!" I retorted, unable to not use sarcasm whenever the opportunity arose.

"Actually I am happy you answered. This will be easier," he said.

It occurred to me it was strange he was calling since he was supposed to be here any minute. "What will be easier?" I asked.

"I am not going to make it to her high school party," he said.

He was a condescending ass, but a football star and ridiculously good looking it seemed according to all the women, so such a shot at high school, where he was just one year ago, wasn't surprising.

"She is going to kill you," I said, knowing she would freak out completely and overreact like she always did when the world she seemed to think revolved around her didn't work out as planned.

"That is why you are going to tell her," he said.

"No way," I said. "They always kill the messenger."

"I have no choice. The big game is tomorrow and the coach, hearing rumours of a big party, put a 10:30 curfew on us and trust me he will check," he said. I love how big strong football players always are scared of their coaches.

"You tell her," I said, imaging the massacre that was going to happen.

"I got to go, good luck," he said, hanging up on me.

I pondered how to tell her the news when a plan suddenly popped into my head. A plan so, so, so wrong, I knew it was so, so, so right. I already knew what his costume was to be because Wendy hadn't stopped talking about it for two months; I also knew it was here because she didn't trust him to remember to bring it with him; it also was a costume that would hide the identity of the person wearing it and also distort his voice. It was perfect. I was going to be my sister's date and if I played my cards right I would fuck her without her knowing.

Before I even had time to really think through the semantics of the plan or decide whether this was a good or bad idea, Wendy walked out in only a towel, not feeling remotely strange to be almost naked in front of her brother, and snapped, "Why the fuck do you have my phone?"

I said, annoyed as usual by her bitchy attitude, "Your boyfriend called and I figured you would want me to answer it."

"He should be here by now," she said clearly annoyed.

"That was what the call was about," I said.

"Don't you dare tell me he isn't coming," she said, her tone threatening me as if the news would be my fault.

"He is coming, but he is going to be late," I lied.

"Why?" She asked already pissed off and grabbing her phone.

"He has a late meeting with the coaches. He said he wouldn't be able to answer his phone either because his battery was dying," I continued to pile on the lies already seeing where this could go terribly astray.

"Fuck," she cursed.

"He asked me to stay here till he gets here," I added.

"And you will," she said, not as if it was a question, but an order.

I shrugged, asking sarcastically, "Of course, what else do I have to do tonight."

"Exactly," she said, which only pissed me off more and made me want to initiate my plan even more.

She stormed off and I smiled knowing she deserved everything that was coming to her and that would be coming into her.

...

Half an hour later, she came down the stairs dressed like a complete slut ... which apparently what makes Halloween great ... a day you can purposely dress slutty if you are a female. She was vaguely dressed as Gwen Stacey while her boyfriend, Kevin, was to be Iron Man. I know it made no sense to me either, but when I asked why she wouldn't be Pepper Potts or even the Black Widow she said because they were old. She obviously had no idea who the Black Widow was or how sexy such a costume would be. I considered questioning why she didn't make him be Spider-Man instead but I assumed it would be more of her insipid logic.

She wore a plaid school skirt, with a black tight blouse, with a white lab coat that said Oscorp, which was the only way you would know for sure she was Gwen. Yet to make herself look even sluttier, she was wearing black thigh high stockings that were completely in view, five inch heels and to finish the ensemble, glasses that I have to admit had my cock harden even more. As much as I despised my sister 99 percent of the time, no one made my cock stiff like she did. My cock was already hard when I saw her legs in thigh highs, my personal fetish.

"What are you staring at?" She asked.

"A slut," I countered, like a brother should.

"At least I can get some," she retorted.

"Dressed like that you are pretty much advertising you are for rent," I shot back, enjoying treating her poorly, something I never did.

"Fuck you, you loser," she snapped.

"Shit, dressed so slutty and you are offering incest," I quipped, foreshadowing what I hoped lay ahead.

"You wish," she said, adding, "Make sure you tell Kevin to get his ass to the party the fucking minute he gets here."

"Oh, I will," I said.

"And call me when he is on his way," she ordered.

"No problem," I nodded.

"Have fun jerking off by yourself," she shot as she walked out.

I smiled as I waited till she left, before I went to try on the Iron Man costume. Lying on her bed was the costume. I looked out her window to make sure her car was gone before I got undressed in her room. I have to admit she went all out on the costume. It was not one of the cheap Walmart costumes as it had real muscles and was made well, yet the helmet was crap. I realized my sudden predicament. As soon as I spoke I would be caught. I went to my room and grabbed my voice activated Iron Man helmet that would distort my voice. I returned to her room, put on the outfit and added my helmet. Looking in her mirror, there was no way to remotely tell it was me.

"Hey baby," I said, practicing in the mirror trying to be suave like Kevin. I waited another hour and a half before going back into her room, pulling out one of her stockings and jerking off so I would last longer when the pivotal moment occurred before deciding to head to the party ... knowing being fashionably late was all the rage ... plus I hoped Wendy would have had a few cocktails, making her less observant and even easier than she usually was.

Giving her a call like I promised, I got a quick confirmation of her alcohol intake. "Wendy, Kevin is on his way."

"What the fuuuuuck," she slurred. "He should have been here an hour ago."

"Don't shoot the messenger," I countered.

She hung up on me. I smiled knowing that the bitch was going to get just what she deserved. All these years of being a stuck-up bitch and dressing provocatively just to tease me is coming back to fuck her in the ass.

Reaching the party, I sat in the car as I started having second thoughts about my plan. Yet, replaying all the bitchy things she had done to me in the past I figured fuck it, and then laughed at the literal meaning of my thought. I had never been to a real high school party so I wasn't prepared for what occurred when I walked in the door. It was wall to wall kids drinking, making out and dancing. I realized instantly finding Wendy would be impossible. I slithered like a lemming going up stream as I searched for Wendy. Five minutes, became ten, became fifteen as I began to feel like I was trying to find a needle in a haystack.

I was just about to give up when I heard my disguised name called out. "Kevin, is that you?"

I turned to see Tiffany, Wendy's best friend, dressed ironically as the Black Widow, wiggling her way towards me.

"Hey, Tiff," I said, trying to sound confident like Kevin would.

"Wendy is pissed, she thought you were standing her up," Tiffany warned.

I replied, "I had to sneak out. Coach put a curfew on us, but I knew I had to be here."

"How sweet," Tiffany smiled, easily impressed it seems.

She grabbed my hand and led me through the throngs of scantily dressed girls and guys trying to get upstairs, to a room at the end of the landing. Tapping on the door she said, "Wendy, its Tiff, I have a surprise for you."

The door opened and Wendy was on the phone. Suddenly I was worried. She turned to me, put her phone down and snapped, "About fucking time. Why are you wearing my loser brother's helmet?"

"It's cooler than the plastic one you left me," I answered.

"Whatever, and why the fuck don't you answer your phone?"

I answered, "My phone is dead, I told Walter that. I had to sneak out and break curfew just to see you."

Instantly her facial expression shifted from anger to puppy dog, it was hilarious but I didn't laugh. She staggered towards me, clearly she had already had a few drinks, "Oh honey, you broke curfew for me?"

She hugged me and I hugged her back.

"I think I owe you something really special for breaking curfew for me," she purred, lowering herself to her knees.

Tiffany said, "I think that is my cue to leave," and she left us alone, unaware she could have witnessed an act of incest any second.

She rubbed my already growing cock through my costume as she said, "I see you have missed me."

Suddenly I realized a problem I hadn't thought about. She had obviously seen Kevin's cock many times, would mine be much smaller or bigger than his. Mine was seven and a half inches which I had measured many times.

"On the bed, baby," I ordered, taking control. Even though I would love to watch her suck my cock, the best way to not get caught was to focus on fucking her where she wouldn't see my cock.

"You bad boy," she teased, squeezing my cock before standing up and sauntering awkwardly in her heels to the bed. I pressed record on my phone and placed it on the edge of the bed knowing this evidence, even if I didn't get any visual, would be great blackmailing material as it would clearly be her voice, but not mine.

"On all fours, my little slut," I ordered, playing my many fantasies in my head out loud. Suddenly I realized I had called her a slut, something I doubted Kevin would ever do.

"Yes, baby," she obeyed, climbing on the bed and lifting up her skirt to reveal she was sans underwear.

I couldn't believe she didn't even flinch at being called a slut. Walking towards her I said, "I think my little slut needs to be disciplined for wearing such a cock teasing outfit to a party.

"You should have seen my geeky brother's face when he saw me in this outfit. The little perv was practically drooling and his little cock was stiff in his pants," she revealed.

I held in a gasp. She talked about me with her boyfriend. She purposely teased me, the fucking bitch. Well, payback is a bitch ... both physically and literally. I kept in my role, "Your brother wants to fuck you, you know that right?"

"That's what makes teasing him so much fun. Knowing that he is probably already in his room whacking off to me is fucking funny," she continued.

"You love getting him hard don't you?" I asked, my hands now on her ass, thinking of using her stocking to come just an hour ago.

"It's fun," she shrugged. "Now are you going to give me some of that iron cock of yours, baby. Your little slut needs it soooo bad."

"Not sure you deserve it," I replied, my finger moving between her legs to her very wet pussy lips. "Your cunt is soaked. Did teasing your brother get you that wet? I am beginning to think you get turned on teasing your brother."

"What?" She moaned, at my touch. "No baby, it's just a fun diversion while I wait for you. Now stop teasing me, I haven't seen you in a week. I need to be fucked hard and fucked hard now," she begged.

My hands moved onto her nylon clad legs another fantasy of mine now a reality. I wanted to kiss her feet, to suck on her toes and to feel her stocking legs wrapped around my naked body as I fucked her, but for now I stayed in disguise and focused on just fucking her.

I fished out my cock and filled her cunt in one deep stroke.

"Fuck yeeeeees," she moaned loudly.

"Tell me how much you love my cock, slut," I ordered, enjoying the warmth of her pussy wrapped around my hard stiff cock buried deep in her.

"Stop teasing me baby. You know I worship your cock," she moaned before surprising me and beginning to bounce back on my cock. "If you aren't going to fuck me, I'll fuck you," she added, as her ass began to move back and forth on my cock.