She had always been like that, always wanting to be tied up, volunteering to be the prisoner in any of our childhood games. Now she was on the very verge of womanhood, her brain still yearned for the days when she felt vulnerable, captive, powerless even. I didn't know any of this of course, I was just sixteen, on the verge of manhood myself. My sister Jenny was two years younger, although her body was developing fast. Already her figure was filling out and her legs were getting longer by the day.

It was New Year in our house, things were nice and quiet for the first time in days. All our visitors had returned home, leaving us all alone. Mum and dad were still sleeping off last night's party, but I was up bright and early to try out my new digital camera. I wasn't alone for long, I just started to load the software onto my computer when Jenny stuck her head around the basement door.

"What you doing?" she asked.

"I'm busy, go and play with your dolls," I said not looking up from the screen.

"I'm too old for dolls now," she said standing behind me and looking over my shoulder; don't you just hate that. I turned around intent on giving her a mouthful, when I noticed that she hadn't dressed but still in her night apparel, in her case a T-shirt over, I suspected a pair of knickers. I tried not to stare but her braless tits were standing proud under her thin top.

"Yes, well," I stuttered, "I'm loading my camera software," I said to her tits.

"Are you going to take any pictures of me?" she asked, well I hadn't planning to. The computer then pinged to tell me it had finished and she reached over me to touch the mouse.

"Stop that," I grabbed her wrist, "you'll bugger it up."

She now tried with the other hand and giggled, which infuriated me even more.

"Will you stop that," I called out, trying not to raise my voice. I grabbed both of her wrists now and got up from my chair and led her over to the couch. I almost threw her down, but I kept my hold of her wrists. She landed heavily causing her T-shirt to rise up over her white knickers and exposed her flat tummy.

"Let me go," she giggled but her wriggling causing her top to rise and expose even more of her body.

"Now sis," I said sitting down beside her, "if you promise not to interfere I let you go."

She calmed down now, her body became still, her eyes closed tight; still holding on to her wrists I looked at her properly for the first time. Boy had she changed over the last few months. A red mist descended over me and I reached out with my free hand. I gently ran my hand over her flat tummy and up as far as the bottom of her top. Above that were her naked tits and although I longed to keep going I knew I mustn't. At my first touch her body twitched slightly, but then she was still again, she made no sound. So instead of going up I went down with my hand, over her hips and then down passed her thighs to her knees. I glanced up to her face, her eyes were still shut tight but her mouth was open, her chest was rising and falling rapidly as she sucked in air. Now I moved my hand up again, this time on the inside of her thighs. As I approached her knickers her legs opened slightly and I could feel the heat coming from her groin.

God what was happening to me, my arms are being held tight above my head and I couldn't move them. It felt like I had a band around my chest, squeezing me, making it hard for me to breathe. I kept my eyes shut tight and I could hear my heart beating fast in my ears. He touched me then, I twitch, I couldn't help it, still he held me tight so I couldn't move. His hand moved up and down my exposed body, my damned fool top was up around my bust. Then as if they had a will of their own, my legs opened for him, oh my, what must he be thinking of me.

I knew what I wanted to do now, the hard cock within my own pants urged me on, but she was my sister, sexy or not and I was not allowed to go any further. But my feverish brain was working on a different agenda to my normal sane one. There was one thing I could do so I let go of her wrists and went back to my computer, the software had finished and my new camera was ready to start taking pictures. I picked it up and went back to stand over her, she hadn't moved so I fired off a couple of shots. After the first flash her eyes opened and she stared up at me; slowly the red mist dissipated.

"There happy now," I said with a smile.

"You're a pig," she snapped and jumped off the couch and disappeared upstairs to her room.

I made it to the safety of my room. I lay down on my bed trying to calm myself, but the feeling of helplessness had left me breathless and yes I must admit it, excited too. I wanted to touch myself, bring relief to my body; my fingers found their way to the spot between my legs and my whole body bucked under their touch.

Pig or not, I downloaded both pictures onto my hard disc. I just about got her all in, long legs and all, what I hadn't noticed at the time was her nipples were standing erect and could easily be seen under her top. Sister or not she had a nice sexy body on her.

For the next hour I tried out the photo package that came with the camera and at last I was ready to print out a copy of my sister; I had blanked out her face though. I heard noises as the house woke up, so I logged off and went to find breakfast.

"Hi mum, sis" I said as I entered the kitchen.

"Hi pig," she said, then with out mum seeing I handed her a print. I watched as her eyes go wide with surprise then she quickly folded it up and put it in her pocket.

"Didn't you like your picture?" I asked the later when mum and dad had gone out.

"What happened to my face?" she asked.

"Well I thought you wouldn't want to be recognised," I said with a big smile.

"I don't mind," she said, "you can show it to who ever you want, I have nothing to be ashamed off."

"Well that's the truth," I said.

Today she was dressed in T-shirt and jeans, she filled them both nicely.

"Will you stop staring at me," she said sternly.

"You've just said yourself that you've got nothing to be ashamed of," I said with a big smile.

He kept staring at me, the pig, and the picture he had shown me, made me feel light headed. I knew he was going to show it to all his mates once we had gone back to school. The thought of him doing so made my pussy gush; I needed to be naked.

"I'm going to have a shower," she said and flounced out of the room.

The thought of her naked body under the shower had already got me hard again and naughty thoughts were running through my mind. I hadn't planned it that way but just as I was leaving my room, heading for the den to watch some TV, she exited the bathroom with a huge bath towel wrapped around her.

"I'll get my camera and take a few of you just like that," I said with a big smile.

"Don't you dare you pig," she snarled.

"Pig am I," I said grabbing both wrist and pulled them high above her head, her back hard against the wall.

"Stop it pig," she snarled, and her body wriggled about.

I waited with baited breath, for if she carried on wriggling like that, the towel was for sure going to become unwound and fall off.

"Let me go pig," she wriggled some more, "oh no," she cried, for she had felt her towel become loose.

"Please I'm loosing my towel," she asked me sweetly.

"Yes I know, but then you have nothing to be ashamed off," I said.

"Oh no, oh no," she cried trying to stand still but it didn't help, the towel heavy with water, unwound and fell like a puddle at her feet.

Oh no, he was holding my hands tight above my head and all I was wearing was a bath towel. I tried to keep still but it became unwound and fell at my feet. I couldn't look at him, seeing his eyes look at my naked body; I closed my eyes tight, I was aware of the pounding of my heart.