Chapter 1

This all started the day I came home, went in the back door to the kitchen and heard soft moaning from the hallway to the living room. I knew my parents weren't home, it had to be my sister.

Curious, I tiptoed into the hall, detoured through the dining room and peeked out into the entrance hall. Looking up the stairs, I spotted my sister, Robin, 'riding' the bannister, one leg on each side, going up and down. As I watched, I could see that she was not wearing panties, her bare pussy was scooting up and down.

I'm no fool, I knew what this was. Pretty inventive too, for a thirteen-year old. Soon, she began to moan, rubbing faster and faster. Then, she orgasmed as her body shuddered and shook.

She wasn't quiet about it either. In fact, she was rather vocal. And she didn't stop. She kept rubbing up and down furiously and climaxed three more times as I silently watched, my cock rock hard in my pants.

Finally, she slumped over the railing for a minute or two, then swung her outside leg back over dismounting the banister and going upstairs to her room.

She never saw me but I can tell you, watching her sure made me horny as hell.

Fascinated, I watched my sister closely over the next few weeks and figured out that she played with herself even more than I did. Lots more, even. She took showers several times each day and I always found the shower head hanging down and set to "Pulse" when she was through. I know what that means and I was pretty sure she was rubbing herself at other times too.

Then, one day about ten days after I'd first seen her on the bannister, I heard some moaning coming from my bedroom. MY bedroom!

As I tiptoed down the hall and eased my door open, there's Robin lying on my bed with her knees spread apart and her panties pulled down to her ankles, her tee shirt pulled up, rubbing her wet pussy and her hard nipples on her pink-tipped young breasts.

Now, my sister is thirteen, just. But she looks more like fifteen or sixteen. Her bra is 36-B (I've looked) and she's very well developed. I noticed some of my Playboys and Penthouses strewn around the bed, she must have found my stash of girlie mags under my bed. And she's really going at it; must be near an orgasm.

As I'm watching her, she opens her eyes.

"Shit. Get the fuck out of here. Close the door. Um, um, oooh."

As she's yelling at me, I can see that she's also having an orgasm as she lays back down moaning and rubbing and out of breath.

I just stood there and when she recovered, she sat up, red in the face, and said, "Please don't tell Mom and Dad, Frank, please." Then she added, "If you ever do, I'll tell them about your porn mags."

"God, Robin, I'm not going to tell anyone. Why should I. Everybody does it. Big deal. By the way, you're very pretty."

She seems to have forgotten that she was basically naked and quickly reached down to pull up the covers.

"Geez, you got an eyeful. Oh, and look at you," she says, pointing at my pants and the rather obvious bulge contained therein.

"You've got a stiffie!" she says as she rubs her pussy under the covers.

"Well, Frank, since you watched me, it's only fair if I watch you do it."

So, I stepped into my room, closed the door and started taking my clothes off. Once naked, I stood there, dick pointing up in the air, took hold and started the familiar sequence that I so well know will lead to arcs of semen spurting from my happy cock.

As I continued to masturbate, Robin did also, now with the covers back down, and seemed to be matching my stroke rate with her rubbing. Soon, we both had orgasms.

"My god, Frank, it really looks wild when you cum. Like a fire hose. Your stuff is all over the floor. Cool."

I sat down on my bed to catch my breath and Robin asked, "Can I do it to you, you know, get you off?"

"Sure, if I can play around with you."

"Um, I don't know. I ... uh ... I don't ... well, okay, I guess so."

She reached over and began playing around with my cock which immediately responded in the expected manner.

"Oooh, look, I'm making it hard again. Feels good, huh?"

"Oh, yeah, really good," I say as I reached down between her legs to her warm, wet lips and began to rub them up and down and circling her clit on each turn.