The sound of thunder woke me.
I listened thinking I had dreamt it then the room lit up and was followed by a loud boom that's when my bedroom door flew open and my 26 year old sister Kelly jumped into my bed.
"I'm sorry Al."
She pushed against me so I wrapped my arms around her, she had always been terrified of thunderstorms.
"That's OK Kel." I said.
I pulled her closer just before another flash followed by a louder clap of thunder that even made me jump, she pushed against me twisting, moaning and squirming, I could feel tears or sweat on my arms and it felt like she was trying to crawl inside me.
"Its OK, your safe with me".
Normally our 12 year old sister Natasha would be diving into my bed but she was away with our mom in London for a late birthday treat.
Over the next hour or so the storm seemed hell bent on scaring Kelly to death, every boom made her whimper and twist in my arms, she would duck under the quilt with every flash of lightning.
Eventually the storm passed and I fell asleep still holding my frightened sister, the house returning to a quiet peace.
Kelly was a tomboy, no other word for it, she was flat and boyish not unattractive but she had always been a tomboy and I thought she was a lesbian because she never had a boyfriend that I knew about.
I have no idea what time I woke up but when I did I realised that I still had an arm across Kelly, who lay face down with my left leg across her legs.
I was shocked when I realised that Kel was naked from the chest down her nightdress must have ridden up during the night.
My erect penis was pressed against her warm right buttock, I always slept nude, I was so hard it was almost painful.
I knew I should move but it felt so good and for a minute or so I lay perfectly still wishing that she wasn't my sister.
I was still a virgin and I knew it was wrong but I had to try something
I slowly pushed my cock against her stopping when Kelly sighed, she moved her hips toward me and my cock now slid between her ass cheeks!
I lay there for an age my aching dick gripped between her cheeks, it was throbbing and wet with pre cum.
I wanted to slide it up and down until I came but what the hell would she say or do?
I knew I should stop what I was doing but I couldn't, I just wanted to feel what that would be like so I slowly moved my hips back then pushed forward feeling Kelly's cheeks around my cock, it felt fantastic!
I paused waiting for any reaction and when non came I slowly pulled back and slid forward again, still no reaction so I repeated the move thinking that if this felt so good, full sex must be mind blowing!
I paused again, this time I pulled my cock as far back as I dared but as I pushed forward my hard dick slid down under her ass and between Kelly's legs the head of my cock must have been right against her vaginal opening!
I froze expecting her to scream rape but Kelly still seemed asleep, I couldn't help myself I pushed forward as much as I could, the tip of my cock felt wetness and was wrapped in something warm, was I inside my first pussy?
I eased back slowly and pushed forward again feeling the warm wetness on the end of my cock the feeling was ecstasy, but my mind was racing and I knew I had to stop but my body seemed to be thinking for itself!
I slowly pulled back and pushed forward again this time I felt myself slid into Kelly gripped again by that warm wetness, suddenly she sighed and in fright I pulled out and away rolling onto my back.
"Why did you stop? "
The sound of her voice made me jump.
"I'm sorry Kel, that was wrong and I shouldn't have done that, I don't know what came over me."
She turned over and faced me.
"I know what came over you, the same thing as me."
She propped herself up looking at me grinning.
"I was enjoying it and I know that you were I didn't want you to stop. "
"What?" I must have looked a complete idiot.
"You heard me" she moved a little "OK, don't move, you've used with me now it's my turn."
She moved quickly and straddled me, lifting herself up with her hands I felt hot wetness against my cock as she sat back lifting her nightdress over her head.
I hadn't seen her naked since we were a lot younger, she was skinny and her tits were small mounds with inviting perfect, pink nipples. Without thinking I reached up and cupped her left tit squeezing it, she grabbed my hand with both of hers pressing it against her, I could feel her nipple harden.
"Oh god Alan!" she had her eyes closed.
"Kelly, this is wrong we should stop. " I said.
"OK, take your hand off me."
She was looking down at me now, she smiled when my hand stayed where it was then I realised she was slowly rocking her hips, rubbing her pussy along my cock.
I looked down and watched the glistening head of my cock appear from her hairy bush as she slid her wet pussy along its length, I grabbed her hip with my left hand pulling her towards me.
"We shouldn't do this." I said again.
"We are not going to have sex and I'm on the pill if anything goes wrong so don't worry" she stopped moving "Al, I have only had sex once and it was awful but this I really want, please let me do this."
I could feel the wetness and heat from her pussy against my cock.
I lifted my other hand and squeezed both of her tits, I was aching to take one of her nipples into my mouth and suck it but I didn't want to spoil the moment, I squeezed her tits and started to roll her nipples with my thumb and finger.
Kelly had started rubbing against my cock again, the sounds she was making were turning me on and the feeling was unbelievable.
I was desperate to suck her nipples so I lifted myself up and placed my mouth over her right nipple as I did Kelly stopped moving, I sucked then moved to her right nipple as I did Kelly moved slightly toward me and I felt my cock slip into my sister.
"Oh yes!" she breathed, a shiver ripped through her and I let out a gasp "Don't move, please don't move Alan."
She was rigid, all I could do was flop back on the bed and savor the feeling.
"Your so big" she hissed "Please let me feel you inside me, please don't move."
I didn't answer, I wanted to be deeper inside her so I pushed up with my knees and hips I felt my cock slide all the way inside her, she gasped her mouth wide open so I grabbed her hips and pulled her down on to my cock to keep her there, feeling every movement of her around my cock.
"Oh Yes!" she breathed.
I pushed my ass down into the bed, feeling my cock slide out a little then pushed back up.
"Don't stop." she grunted.
I was fucking my sister!
It felt fantastic and I couldn't believe what I was doing and I couldn't stop.
She put her hands on to the bed either side of me, her face close to me, then she kissed me hard.
"Please don't stop."
I could feel her tight vagina around me, every thrust into her seemed to make me harder.
"Oh god Alan your making me come."
Her hips were getting faster and she moaned every time my cock slammed into her, I could feel my orgasm building.
"Kelly, I'm coming, I can't stop."
I was slamming into her faster and harder, my fingers were digging into her hips as I pounder into her.
I could feel her get tighter around me.
"Yesssss." she hissed through her teeth.
As she did I gave a massive push into her and came in long waves, I could hear myself saying her name every time my cock slammed and pumped inside her, it felt as if I was shooting pints into her I came so hard.