My mother died in a car accident when I was around six years old, my dad was devastated, but two years later he found someone else, she was a single mother, her daughter was seven when we met.
Hello my name is Nathaniel but everyone just calls me Nate, I'm 18, I'm about 6'1" I have light brown hair with grey eyes. My step sister is Cassidy everyone calls her Cassi or Cass, she is 17, she's about 5'5" she has dark blonde hair with bright blue eyes. My dad and my step mother Lauren are going on a cruise for a week for their tenth anniversary and during that time I'll be looking after Cassidy.
Before they were set to leave I was given a list of what i could and couldn't do during their time away, where everything should be, numbers to call, not to have any parties or girls over, you know, all the stuff parents do before they go out, given lots of hugs and kisses, they told Cassidy to do everything I told her because I was in charge. As they were leaving we waved goodbye, 'lets go inside and I'll order us some pizza and a movie' I said, she said 'sounds great' And we walked inside.
After dinner we decided to watch another movie, and when that finished we both went to bed. The next morning I had to take care of my morning wood and shower so I got my towel and walked to the bathroom beside Cass' room.
As I was passing I heard I small whimper, I stood there listening, and when I heard a load groan I decided to check it out. I threw the door open so forcefully that I'm surprised the door didn't come off its hinges. The moment the door opened was the moment that changed me forever. Cass was on the bed looking up at me with a shocked expression, while I was frozen.
As I stood there dazed Cass started screaming at me 'GET THE FUCK OUT!'. I had never heard her use such language, I shook my head to clear it of the haze.
When my vision cleared I followed the length of her arm down to her glistening pussy. My jaw nearly hit the floor and I'm sure a little bit of drool came out of my mouth.
'Wow' I breathed. She screamed again. 'Oh' I turn away. When the rustling of clothes has stopped I turn back around to see her face flushed with embarrassment, I realise when I notice her staring at the tent in my shorts. Now it was my turn to blush. She had recovered and now she was pissed. 'What the hell?
Why'd you just burst in without knocking?!' 'I . I heard a noise and I thought you hurt yourself!, I was only trying to help. If I had of known you were doing. THAT, I would've never walked in!.' I left the room as fast as I could, and ducked into my room leaning against the door.
The shower long forgotten as my cock begged for attention, I thought just once and I'll never do it again. So I fished my cock from my shorts, harder than its ever been before.
As I stroked it felt better than when I've thought of other girls, I'd never been hornier, especially for my younger step sister. I lock the door and lay on my bed and start stroking again to the image now burned in my mind, my mind made up a scenario that when I burst into the room she'd come up to me and we'd have passionate sex.
I'd never cum harder. Shooting rope after rope imagining it was her mouth catching my spillage and not my hand. When lunch came I couldn't avoid natures call anymore, I was also terribly hungry, so I snuck out of my room trying to avoid her for longer so she wouldn't see the shame and guilt on my face, but when I got to the kitchen there was a note on the counter addressed to me, it read 'I'm going to hang out with some of my friends, I'll be home before dinner love Cassidy xx' I was overwhelmed with relief, she wouldn't know but I will so I decided to make her a special dinner, I got in my car and made my way to the supermarket.
When Cassidy came home dinner was coming out of the oven, I told her to sit at the table, she went to sit down and I asked her how her day was she said 'it was fine, what's with this?' I said 'nothing, I just wanted to make something nice for dinner' as I set the food on the table. We ate and talked about nothing in particular. Then the topic of girlfriends came up, 'so is there anyone special, you know, a girl?' Cassidy teased, I said 'nah, you know there's no one I'm interested in now, what about you?
Any guys I need to beat up?' She giggled 'AS IF! You know I'm not interested in anyone either', 'alright, do you wanna go find a movie to watch while I put everything away?' I asked, 'sure' she replied.
The movie she picked was a scary one, so we got a blanket and snuggled up on the couch, during a suspenseful scene, she got even closer and jumped when the guy on screen was shot, basically sitting in my lap, I thought 'oh no!
I hope he doesn't wake up' but of course no sooner as the thought finished he started to lift up, so I shifted so she wouldn't notice, but that just made it more noticeable, she squealed 'what is that?!' I jumped up, my shorts tenting, as she ran from the room the hers, I ran after her, as she slammed the door in my face, I told her desperately 'I couldn't help it!!
When a pretty girl sits on my lap I can't control it, I'm sorry!' 'Just leave me alone!' Was the only response, so I went to my room and after countless hours fell into a restless sleep.
I've been trying really hard to figure out the next part of the story line, but everything I've tried has just seemed forced and it just would not fit well at all. So if you'd be kind enough and leave some concepts that I could work with another part will be coming soon.