I thought that would be a one-off but over the next week or so our little 'play' sessions always included some oral sex. My little sister clearly liked having her pussy licked and she seemed quite happy to give me a blow job.

That hard core porn magazine played a big role in how things progressed. Emma spent a lot of time not only looking at the pictures but reading the stories too. She surprised me on one occasion when she not only took my full load in her mouth but swallowed it all too! Apparently it was something she read in the magazine!

There was one thing the mag was full of that we hadn't done yet... fucking! I really wanted to do it but I was actually scared of it. After all we had done together it seemed a step too far! I was worrying that Em was just a little kid and my sister too. It was really starting to feel wrong! Emma had also been thinking about fucking but she was unaffected by the guilt I was feeling about all this. So once again it was her that moved things along to the next step.

"Ross?" Emma asked. We were in her room, partly clothed and idly playing with each other. She was slowly flicking through the well thumbed porn mag. Dad was at work and Mom was in the kitchen having one of her frequent coffee mornings with some of her friends.

"Mmm, hmm." I replied without moving my lips from one of her little titties.

"I think we should do this." she said casually pointing to one of the pictures. I looked up, still not releasing her erect nipple from my mouth. The picture showed a close up of a guy's huge cock buried to the hilt in a girls wet cunt. I froze, her nipple finally slipping out from between my lips. "Err, don't you think that's a bit too grown-up for us?" I stammered. "We're still just kids after all!"

"Why should all the nice things just be for the grown-ups?" she complained. "I still think we should do it. We've done all this other grown-up stuff anyway!"

"I dunno Em! It just seems wrong somehow."

"You're just scared." she challenged.

"No I'm not, I want to do it too. I just think we're too young." I replied. "Well you are anyway."

"Funny how you think I'm not too young to suck your cock!"

"That's different."

"IS NOT!" she challenged.

"Shhhh!" I whispered. "mom will hear!" We both turned towards her bedroom door which we had left ajar so we could hear if mom was coming upstairs. All we heard was muted voices and the occasional chorus of laughter. "That's another reason we shouldn't do it," I continued "mom will catch us and then we'd be in real trouble!"

"I don't mean now stupid! Next time mom is out."

"Well..." I was running out of argument.

"Scaredy-cat." she challenged with a smile, knowing she had already won.

An opportunity didn't come for another two days. Mom went out shopping and left me to look after my little sister. She wanted Emma to go with her but Em faked feeling ill. As soon as mom's car disappeared down the street we rushed up to my room and hurriedly undressed as we usually did.

"We're gonna fuck today aren't we?" Em asked breathlessly.

"Yep, if you still want to." I was as keen as my sister having had two days to wonder what it would feel like. She dived naked on my bed, legs open as she usually did when she wanted me to lick her pussy. I looked down at her and wondered what to do! My cock was about half hard as I knelt between her skinny thighs.

I lay on top of her like one of the guys in the porn mag. My cock pressed on Em's crack and it did feel good but it didn't go into her cunt! The problem was I knew I needed to get my cock in her hole but not how to do it.

"I don't think it's in yet." Emma stated unhelpfully.

"I know!" I grumbled with frustration as I knelt up and thought about the problem. Taking hold of my cock I held it against my sister's pussy lips and tried to keep it there as I lay back down.

"OW!" Emma gasped "You're squishing my pussy!

"I think you need to pull you pussy lips open so I can get my cock in!" I'd remembered on of the pictures in the mag that showed a woman pulling herself open. You could see all the way into her hole! Emma pulled her nether lips apart and I tried again. I immediately felt her moist juices lubricating my cock.

"That's it!" Emma gasped as my rigid tool found the entrance to her little cunt. I pushed slowly in and felt my cock head enveloped in wet warmth but there was some resistance. "Ow!" Emma winced.

"Are you okay?" I pulled back out thinking I'd hurt her. "It does feel kinda funny, it's okay though." I pushed back in and once again Em winced and stiffened up as I got to the resistance. "Don't push in so hard!" She complained. I eased back, confining myself to gentle insertions of my cock head into her pussy entrance. It did feel really good which made up for the disappointment I felt that all of my cock didn't fit in. I guessed she was just too young!

Emma sighed with pleasure too and I felt her relax. She even started pushing her hips up meeting my down stroke. I was sure it felt like my cock was going a bit further in. Suddenly I felt whatever was causing the resistance release and another couple of inches of rigid cock slid in. I froze expecting Em to be hurt but she just drew a sharp intake of breath and looked at me wide eyed.

She started moving her hips again so I continued the rhythmic in-out strokes. My cock was definitely going in deeper now. This was really good. Emma's eyes were closed now and she breathing deeply. We were both so engrossed in what we were doing I doubt we would have heard if Mom came home and caught us!

Emma was making all the noises she usually made just before cumming when I finger fucked her so I knew she was close. Still, I wasn't prepared for it when she did reach her orgasm. Her cunt muscles contracted, squeezing my cock and driving me over the edge. I could feel the pressure rapidly building and I responded by humping her faster. My throbbing cock exploded deep in my little sister's preteen pussy, filling her with my full load of cum. That had to have been the best cum of my life!

After that first time, Emma was insatiable! Well, if I'm honest, so was I. We would get together and fuck any spare moment we could find, which was pretty much every day and sometimes twice in a day! Our childhood was never the same again as we continued to fuck each other right up until the day I got married, literally! But that's another story.