Two weeks before Halloween I recieved an invite to a fancy dress party. It came in an envelope with no writing on it and the address on the invite was one which I didn't know. I'm a person whose up for anything and with no plans for that night thought what the hell. I rang my sister to see if she knew the address and she said no but that I should go anyway as it might be fun. She asked me what I was going to wear and I told her.

The night of the party arrived, so off I went dressed as Batman. Pretty corny I know but it was the only thing that I could find which covered my face. Arriving at the address I was given it turned out to be an unused warehouse. I walked to the door and entered to find the party in full swing. There must have been well over 200 people dancing and drinking.

I made my way to the bar to get a drink and take in the crowd. I was sitting there just watching and wondering why I hadn't stayed at home as I knew no one here. I was finishing my third beer getting ready to go when Catwoman cones up and asks for a dance. Not wanting to be rude and thinking that my night could get better I accepted. We'd been in the dancefloor for a couple of songs when she suggested we grab a drink and head outside for some fresh air.

Outside in the fresh air I got my first good look at her . She was about 5"6 slim build and the catwoman costume was hugging every part of her body. It was so tight I could tell she was naked underneath. I hoped I'd be seeing her naked by the morning. We started chatting and found out we had a lot in common. One thing I found strange was how many mutual friends we had.

As we continued talking I couldn't but stare at her gorgeous body underneath her costume. I was staring at her rits when she asked if I'd like to see them as I'd been staring at them all night. After I apologised to her she asked again if I'd like to. Seeing as I'm a gentlemen I said I'd love to. Without hesitating she unzips her topand frees the firmest pair of tits I've seen. I've seen breasts like this on one other person and that is my sister and that was only by accident.

I couldn't resist and moved my hands out to touch them. She didn't move away so I touched them. My god they were so fucking soft. I started to gently squeeze them and play with her ever hardening nipples. Feeling boulder I lent in to take a nipple in my mouth and gently lick it. She pushed it into my mouth and told me to bite it. I did as she asked enjoying the feel of it getting harder and harder. I heard her moan just softly over the sound of the music .

My hands wandered all over her body , from her shoulders to her firm ass. By this stage my cock was as hard as a rock. She asked me to stop and sit down on the seat behind me. Sitting down she knelt before me and started to unzip my costume telling me she wanted to see my prick. Once she had me free and in her hand she started to run up and down my 7" cock. This lasted for a couple of minutes before she took me in her mouth.

She only took about half in her mouth still jerking me off with her hand. I leaned back taking in how good it felt to have her sucking on my cock. She would take me out and run her tongue up and down my shaft and around the head. She was taking more of me in her mouth and I felt the back of her throat once or twice. She moved her hand away and with one movement took all of me into her mouth and down her throat. No one has ever deep throated me and all of my hardon was in her mouth I couldn't hold back and came in her mouth. She held still as I shot my load into her mouth and throat. Taking her mouth of me we kissed and I tasted my cum mixed with her saliva.

She took my hand in hers and moved it between her legs. I rubbed back and forth feeling her heat. I moved my hand up to wear her zip was and undid it. I felt wear her panties should be and feeling nothing but smooth skin went lower. My fingertips touched the top of her pussy. I began to slide my fingers along her lips before moving to her clit. Finding her clit erect I slowly circled it moving closer and closer until I was sliding my wet finger over it. Her moaning had become louder and she told me not to stop as it felt so fucking good. Her hand was resting on top of mine dirrecting me in how she liked to be played with.

I looked at her face ( or what I could see under het mask ) to see her biting her lip. She moved her hand of mine and slid a couple of fingers inside her hot cunt. A few minutes later and she was cuming. The grip from her legs meant I had to leave my hand where it was, all covered in her wettness.

She noticed my cock was still hardand asked if I wanted to fuck her wet pussy. We stood up and took of our costumes but leaving our masks on. Not caring who saw as we had one thing on our minds she bent over the chair and told me to fuck her hard. I stood behind her and slid inside her cunt.

I let her get used to me before I fucked her pussy with long hard thrusts. She was pushing back onto my cock telling me to fuck her harder. I was almost slamming myself into her as she reached down to rub her clit as I fucked her. I was thrusting ad hard ad I could when she exploded into orgasm. Her pussy muscles grabbing at my cock as I too came. The sensation of what she was doing sending me over the edge as I came deep inside her pussy. I pulled out and shot the last of my come over her back before resting on the chair next to her.

She sat down beside me and I noticed her mask had come off. Turning to face me I was stunned to see I was staring at my sisters face. I started to say something but she told me to be quiet. She told me she had always fantasised about fucking her big brother ever since she saw me in my room jerking off. Shed played with herself thinking how it would feel to have my cock inside her. Now she had felt what it was like she asked if we could continue to fuck each other.

I told her I would love to as long as no one ever found out, to which she promised it would between her and me.