It was the second week of our summer break and I was already bored. My older sister seemed to have plenty of friends to visit but my few were away on holiday with their parents. I woke late last night to hear Alex creeping in from wherever she had been, luckily for her, our mum and dad sleep very soundly. The front door slammed and we were alone once again for the summer break doesn't stop mum and dad from working.

It doesn't take a rocket scientist to recognize that smell, I'd been to a few parties where a joint had been smoked and now I could smell it again.

"Shit," I said out loud.

That stupid sister of mine was actually smoking it in the house. Stupid she may be but she easy on the eyes, real eye candy material.

"I wouldn't smoke that in there," I said after knocking on her door.

"Go away, you little shit," she said.

"Ok," I said walking away. "But don't blame me if you get grounded."

"What?" she snapped as her door opened.

She wasn't completely dressed, she had just pulled a dressing gown over her bra and knickers and that wasn't tied too well; it was quite a lovely sight.

"Look, sis," I said eyeing up her exposed body.

"What are you gawking at?" she snapped pulling her gown closed.

"The smell, you fucking idiot," I said.

"Oh," she said with a weak smile.

Like I said, nice to look at but not much upstairs. I went back to my room, well, I had home work to do although I didn't feel much like doing any.

"Can I come in?" she asked poking her head around my door.

"Sure," I sighed.

She still hadn't dressed but her dressing gown was tightly wrapped around her.

"You won't rat on me will you?" she asked looking slightly pale.

"Of course I will, you stupid cunt," I said with a laugh.

Well, I wasn't thinking of doing anything of the kind but sometimes her attitude gets up my nose.

"No, please don't," she squealed.

The panic in her voice was lovely to hear.

"You've only got yourself to blame," I said with a laugh. "You treat me like shit then expect me to be nice to you."

"No, I'll be nice to you from now on," she squealed again. "I promise."

"Yeah, right," I said turning away. "If you're going to be nice to me, why don't you take your dressing gown off."

I waited for the explosion and I wasn't disappointed.

"What! You little shit," she shouted. "I won't do that even if I was grounded for a month."

"Be more like a year," I pushed.

The door slammed in her wake and I burst out laughing.

"A year, at least," I shouted.

Fun over and now there was English homework to do.

I was struggling with my nouns and pronouns when she knocked on my door again.

"Come in," I said.

"Hi," she said sounding like all sweetness and light. "You're not really going to grass me up, are you?"

"Good choice of words, sis," I said trying to keep my face from smiling.

"Look, it was only a small one," she explained, "Betty gave it to me last night to try. It was my first time, honest."

"Let's see if dad believes you, shall we," I said.

"No, please don't," she wailed.

"Well, you know what you have to do," I said.

"Look, you're my brother," she said.

"So?" I replied.

"So, if I do this you won't tell?" she whispered.

"I can't promise, sis," I said loving the way she was suffering. "As I said, you're always shitty towards me and it would show good faith that you won't be in the future."

I could see she was trying to get her head around that. In the end, she just shrugged and untied her belt.

"No touching," she said, but didn't wait for me to reply before her gown dropped to the floor.

She wasn't wearing anything particularly sexy, just your ordinary twin set but her young firm body shone through. Oh, she knew what she had, all her boyfriends, and she had plenty, would have told her what a fine body she had and now she stood like a model and she even pushed her lace covered tits out towards me. Despite the situation, I could tell that she was loving it, loved exposing herself even if it as only to me.

"What do you think then?" she asked with the slight sound of excitement in her voice.

"Very nice, sis," I said moving a step closer. "What are you vitals?"

"What?" she said, a frown replacing her smile. "Oh, you mean my measurements."

"Yeah," I said.

"Well I'm 34 C here," she said cupping her tits. "24 here and 35 here."

Her hands moved down over her body to empathise her words.

"Very nice," I said again and moved closer still. "You should be a model."

"Yeah, I keep getting told that," she said with a giggle.

"Sweet 16 and never been kissed," I said, moving ever closer.

"I wouldn't say that," she giggled again. "After all, I am 17."

"Sweet 17," I said, "Isn't there a Beatle song about being 17."

"Is there?" she said.

"Yeah," I said.

I was close enough now to put my arm around her trim waist and lean forward to kiss her neck.

"Stop that," she said with a giggle.

"Beautiful, just beautiful," I murmured.

"You won't tell any one about this, will you?" she said, her voice just a tad breathless.

"No, no," I said off hand for my hands was now moving over her near naked back.

"And you promise not to tell dad about me smoking?" she said.

"We'll see," I said.

"No, please, brother, you won't will you?" she said.

I moved my other hand up between us and cupped her 34C.

"Depends," I said as I gently squeezed her.

"No, please," she said, "Look, I'm being all nice to you."

"Mmm, so far," I said moving my hand to squeeze the other one.

One handed, I unclipped her bra strap and now it was loose I could get my hand under it and feel naked flesh.

"We shouldn't be doing this," she said her voice changing again.

"Great tits, sis," I grunted.

I bent down and took one erect nipple between my lips.

"Oh," she cried out. "No, you mustn't."

The backs of her legs were up against my bed now and with a slight push she tumbled on to it, and all without my lips breaking contact with her nipple. I suppose she was used to being under some guy or other so when I fell on top of her, her legs just naturally opened and I settled between them. I wasn't really in the right place just yet, too far down her body for my lips were still attached to one nipple while my right hand was thumbing the other but when I let go and moved up her to kiss her on her lips I was just right for my hard cock to rub against her nylon covered pussy.