One thing I had never been able to resist was a dare, it had got me into trouble more than once, but any time someone said 'I dare you' I'd take up the challenge with a laugh. I was fourteen when one of my school mates started going on about having seen his little sister in the nude, I suppose that at that age we were just starting to take an interest in sex and his claims were greeted with both derision and excitement.

"Shit," one of the crowd exclaimed, "what's so good about seeing a twelve year old girl in the nude. Now if it was an older girl that'd be different."

"What about your sister Don, ever see her in the nude?" one of the other boys called out to me.

"Nah," I replied, "I mean, who wants to look at their own sister?"

Mind you my sister was seventeen and by all accounts she was a right cracker, I suppose she was, but as her brother I had never looked at her in that way so I was no real judge. The group laughed and joked about the subject a little longer and the topic was just dying down when some bright spark yelled out.

"Hey Don, why don't you spy on your sister and tell us what she's like with no clothes on."

"We dare you." One of the others yelled.

Of course that was it, the magic words had been spoken and I laughed and accepted their challenge vowing to not only see her in the nude but to try and get a picture of her as well. It was the last day of school and I had six weeks to try and meet the challenge that had been given to me. I knew it wasn't going to be easy, especially with my parents around, but I also knew that I'd figure out some way to do it. Luck played into my hands right from the very start, my parents announced that they were going away for three weeks and that while they were gone Kay would be in charge, I rubbed my mental hands at the thought that I would not have to cope with my parents while spying on Kay. A couple of days later my parents were gone and Kay took charge, not that I minded much, with her in charge I had a hell of a lot more freedom than I usually did and I spent most of it plotting ways of seeing my sister in the buff.

A week passed and I was beginning to think that I would fail to meet the challenge, I so rarely failed that I felt depressed and one evening I snuck a few snorts from dad's scotch.

"What are you doing?" Kay asked making me jump.

Guiltily I put the scotch bottle down and gave her a weak grin, she shook her head and laughed then pointed at the couch, meekly I went and sat down.

"I know you Don," she said firmly, "something's bothering you, come on, out with it."

After some pressing I confessed what I was up to, I told her the whole story and waited for her to burst out laughing or to get hopping mad, instead she confused me by grinning.

"God, you and your dares." she sighed, "One of these days they'll be the death of you. When will you learn some sense? So you're feeling down because you can't find a way to meet this challenge of seeing me in the nude and taking a picture of me that way, is that right?"

"Yes Kay." I said hollowly.

"So where's your camera?" she asked.

"Upstairs in my bedroom." I replied in a puzzled tone.

"A lot of use it is there," she grinned, "come on, let's go get it."

I was totally confused as I followed her upstairs, while I grabbed the Polaroid from my room Kay waited on the landing for me to reappear.

"How many pictures are there in that thing?" she asked.

"Ten." I replied.

She grinned and crossed the landing to our parents' room, she opened the door and beckoned me to follow her, which I did. Inside she went over to the large double bed and sat down on the edge of it.

"Right," she said leaning down to take off a slipper, "I'll pose for your pictures, all ten of them, but boy will you owe me big for this."

"You mean you're going to...?" I gasped as she took off her other slipper and started to open her blouse.

"I'm going to strip off and let you take your pictures." she grinned shrugging off her blouse, "Unless you don't want me to that is."

"NO! I mean, yes, I want you to, but why?" I said hurriedly as she stood up and fiddled with her skirt.

"I've my own reasons." she grinned, "If you want me to go on then don't ask any questions."

"Okay, no questions." I breathed as I stared at her panty and bra clad body.

"Like what you see so far?" she asked as she reached behind her to undo her bra.

"Oh yes!" I sighed raising the camera.

The first picture I took was of her sliding the bra down her arms, I could see her boobs fully and noticed how hard her nipples looked as she smiled at me. My next picture was of her crouching to remove her panties, her boobs hung in the foreground like tempting fruit and I felt my cock suddenly getting hard; as she straightened I wriggled in an effort to ease the pressure on my cock. It did no good for one sight of her pussy had my cock as stiff as an iron rod, I groaned to myself as I took the third picture with my sister standing and smiling straight into the camera.

"You look uncomfortable." Kay laughed as she saw me wriggle again, "You can't take decent pictures wriggling like that, tell you what, get stripped, that'll ease the pressure at least."

Laying the camera aside I quickly ripped off my clothes, she was right, as my underpants slid off the pressure on my cock eased a lot. However, the excitement I was feeling was no less and I was more than a little surprised that my own sister was turning me on.

"Nice cock." Kay commented as I raised the camera for the next shot, "How would you like me?"

"On the bed." I said blushing at her compliment.

"Like this?" she asked lying back on the bed and letting her knees part.

I gulped at the sight of her pussy as it was revealed in all its glory, my hand trembled as I raised the camera and I had to take a few deep breaths before they were steady enough to take the picture. For the next fifteen minutes my sister posed for me, as I took the last picture with her kneeling on the bed looking back at me over her shoulder I licked my suddenly dry lips. The camera was empty and I put it down beside the ten pictures I had taken of Kay, she grinned at me without changing her position and I felt my eyes being drawn to her pouting pussy.

"What's the next pose?" she asked over her shoulder.

"I've no more film." I sighed in reply.

"So." she grinned, "I haven't had this much fun in ages. Just pretend I'm your model, now how would you like me? I know how about a close-up?"

Dumbfounded, but more than willing to play along I stepped right up to the side of the bed, Kay lay on her side and smiled up at me. There was something wild about her eyes and I wondered if she had been drinking or something before she had caught me. Whatever her reasons I found that I wanted to keep on looking at her for as long as I could, grinning I held an imaginary camera and said 'click'. Kay laughed and adopted another pose, which I 'snapped', and then I had a devilish thought.

"How about a raunchy one for the older readers my dear?" I said in the role of a professional photographer.

"How's this?" she asked cupping her tits.

I stared at her tits for a moment then pretended to take a picture.

"Good, but not quite what I meant." I said softly.