Things stepped up a gear the day my best mate, Tommy, loaned me a particularly hardcore porn magazine he'd found in his dad's closet. I had left it out on my bedside table when my little sister came in for one of our 'jack-off' games.

"Hey! What's this?" Emma exclaimed!

"Oy! Leave it alone, it's not yours!" I made a lunge for the magazine but she deftly twisted away from me. I grabbed her around the waist and pulled her down onto my bed, and tried to wrestle it off her.

"Stop it Ross!" She giggled as she rolled onto her tummy on top of the book. " I just wanna see it."

"Give it back." I pleaded. "It's not mine and your making it all creased!" I tried tickling her. This usually made her dissolve into a giggling wreck, unable to do anything but she stubbornly held on to the porn mag.

"Okay! Okay!" She laughed. "I'll let you have it but only if you let me look first."

I couldn't think of a good reason not to let her look. "Okay then but you won't like it!" She sat up and started eagerly turning the pages. The magazine was a particularly graphic hard core publication, quite different to my usual mag that only had pictures of naked women.

Emma turned the pages more and more slowly, her eyes growing wide at the pictures of erect cocks penetrating open pussys. "Wow!" Her voice was almost a whisper. "Is this what sex is?"

"Yup, that's right." I replied. "Told ya you wouldn't like it." She didn't respond. She had turned the page to a sequence of pictures showing a girl sucking a guy's cock and the look on her face made me giggle.

"Ew! Why is she doing that?" Em exclaimed!

"That's called a 'blow job' and it's supposed to be really nice." I tried to sound knowledgeable on the subject but the truth was these pictures were also my introduction to a practice I'd only heard talk about from older boys.

"Doesn't look like she's blowing on his cock!" Emma frowned.

"No silly! She's sucking on it."

"No, you're silly, it should be called a 'suck job' then. Looks yukky!" She pulled a face.

"Guys can do it to girls too, you'll see in a few pages."

Em kept slowly turning pages and studying the pictures with interest, especially the ones of the guy licking the woman's pussy. "I want you to do that to me." She stated. The thought of doing that made me cringe because it seemed quite a dirty thing to me too but a part of me was curious and the twitching of my cock was unmistakeable.

"I dunno!" I hedged. "It's a bit too weird and grown up don't you think?"

"Chicken!" She challenged.

"Am not! I was just thinking you're still a kid."

"Your a kid too... you're just a scaredy-cat."

"No I'm not! I don't mind doing it but you have to give me a blow job too." That silenced her. She turned the pages back to the cock sucking pictures whilst she considered the idea. Em suddenly closed the magazine and gave it back to me.

"Okay... I'm game. Lets do it!" She announced. We both undressed unselfconsciously and Em lay down on my bed, legs open. I stood looking down at her with butterflies in my stomach, wondering what I had got myself into! "C'mon!" Said Em.

I briefly considered getting her to do me first but it wasn't worth the argument, I'd have to lick her pussy afterwards anyway so I might as well get it done now and have the blow job to look forward to later. I knelt on the bed between her legs. The familiar sight of her preteen pussy and the faint musky odour tainted faintly of piss still excited me. I wondered what it would taste of as I placed my puckered lips on her crack giving her a chaste kiss. It was quite nice and I didn't puke or anything so I kissed her pussy again.

"Wow!" Em gasped. "That's pretty cool." She pushed her cunt against my face. I felt her pussy lips part and I could feel the little hard nub of her clit on my top lip. I quickly poked my tongue out and tentatively tasted her juices. It was a little tangy but not unpleasant so I did it again. This time my tongue brushed her little clit and Em flinched! I backed off thinking I had hurt her but Em said "Oh my god, that's good! Do it again." So I did.

I continued playing my tongue over Em's pussy as if it were my finger, even dipping the tip into her cunt hole. Emma groaned, pushing herself against my face and gyrating her hips. I found the whole thing very exciting. My cock was rock hard and was soon stroking myself.

My sister was soon approaching orgasm. I had fingered her to enough to recognise the signs but this time it seemed much more intense. Her face had gone bright red, she was breathing heavily and moaning and her hands were gripping the bedding. Suddenly Em cried out. "Oh yes!" Her legs closed on my head, crushing me just as she does with my hand. She arched her back and rammed her pussy forcefully into my face. I felt my nose being squashed into the soft mound of bald flesh above her crack.

Her cum lasted longer than usual, a lot longer! I had to hold my breath for most of it! My face was covered with her juices. Finally Emma relaxed, releasing my face. She lay back panting and spent. I collapsed too with my face on Emma's chest and we lay together like that for a while, both of us getting our breath back.

I was looking at Emmas's little boobies up close. I hadn't noticed before but they were just small cone shaped lumps behind her tiny nipples. There were plenty of pictures in the porn magazine of guys sucking on girls titties and my sisters immature bumps looked inviting. I slipped my mouth over one and sucked, sliding my tongue over her nipple and felt it stiffen in my mouth.

Emma giggled "That tickles!" I moved over to her other tit and gave it the same treatment. "But it feels nice though!" I thought so too but Foremost in my mind was the blow job she'd promised me.

"Okay Em," I said as I sat up. "You said you'd give me a blow job."

"Yeah." She sighed. "I did didn't I."

We changed places, me lying down and my sister kneeling between my legs. She looked a bit reluctant or perhaps just unsure what to expect or how to start. I was worrying she would back out but she picked up the magazine and studied the blow job pictures again before taking hold of my cock.

She started by licking the tip of my cock. It was electric! My juices were already flowing and the slimy fluid stretched up to her lips as she pulled away. Em licked me a few more times, each time becoming bolder until she opened her mouth and slipped her lips over my throbbing shaft. She held me in her mouth and I could feel her tongue exploring the top of my cock. The feeling of my sister's mouth around my cock felt wonderful but I needed more, I needed movement so I started humping Emma's face.

She looked a little startled at that and flashed me a 'What do you think you're doing?' look. She let me continue though and I guess she decided, like me, that this was no different to to doing it with your hand except you use your mouth instead.

I continued humping into her mouth and Em began bobbing her head up and down and jacking the base of my cock with her hand. It was a bit disjointed to begin with but we soon got into a rhythm.

It didn't take long! I soon felt and enormous pressure building in my cock and I knew I was about to erupt. I briefly wondered what I should do? Do I let it squirt in her mouth? Do I pull out first? Should I warn Emma and let her decide? The pictures showed cum both on the girl's face and in her mouth. In the end I didn't really care! I needed to cum and surrendered myself to the moment.

"Aaaaargh yes!" I groaned. The first rush of cum was electric. The look on Em's face was priceless as her mouth filled with cum from the first shoot. She pulled back just as the second shoot erupted splatting over her face in a line from her left eye across her cheek and lips to her chin. The rest of my cum boiled out as I continued to hump her fist and ran down my shaft and over her fingers.

Emma was making "Ughh!" noises as she attempted to spit my cum out. The expression on her cum splattered face was so funny I burst out laughing. Fortunately she saw the funny side too and erupted in a fit of giggles.