Spying On My Step-Sister

My parents got divorced when I was in middle school and my dad and I moved to Chicago from rural Montana. He worked at a law firm, and we got a pretty nice apartment downtown, in an old building that was renovated. I guess my bedroom had been half of a bigger room before the renovation, and the contractors had just used plywood or something to build a new wall to separate the room into two. (This is going to be important later, I promise).

I didn't love starting high school in a new city, without any friends, but one thing I did like was that the city girls were just way hotter than the country girls I was used to - at least, that's how it seemed to me at the time. I was way too shy and nerdy to talk to any of the popular kids at school, let alone the girls, but believe me that I jacked off A LOT to some of the curvy, blonde juniors and seniors.

Flash forward a year, and my dad had met this woman who worked at his firm, and got married again. She was a single mom, and I got to know her a fair bit before they got married, obviously, because she was around a lot (some other stories there... maybe for another time). But they got married pretty fast, and I never met her daughter before the wedding, though my dad did, and told me she was about my age.

At the wedding, we meet for the first time, and I'm instantly like, holy shit, it's Kacey - one of those blonde seniors I used to jack off to. She had graduated, and was at UChicago. She did not recognize me, but I absolutely recognized her. She was still super hot, probably 5'5 with long blonde curly hair and a thick ass and little waist, but her best feature was definitely her juicy round tits, not too huge, but plenty big enough. She was pretty nice to me, but I was definitely super awkward.

About a month later, they moved into our apartment with us. Kacey got the bedroom next to mine - the one that used to be the same room. They moved in while I was at school, and when I came home that day, they were already unpacked. It definitely took some serious adjusting to having them around, but there was one massive perk that I discovered that very first night. I guess Kacey had been hanging art or posters on her walls, and made a bunch of different holes in the thin plywood. There were a couple of nail tips that kinda poked out of my wall a little, but there was one hole that I guess she had changed her mind about, because it was just a full on little hole between our rooms, just a little bit above my eye-level.

After dinner, I was getting ready for bed, and I heard her moving around in there. Needless to say, I was hard as fuck even just hearing this smoking hot girl in her bedroom so close to me. When I turned off my light to go to sleep, there was a little beam shining out of my wall, and when I went up to it, I realized that if I stood on tip toes and pressed up against the wall, I could see into the room. It was a tiny hole, and a shitty view, but remember that at this point I'm a dumb horny teenager. I looked through, and almost nutted in my pants.

Kacey's bed was across from the wall, and through this little peep hole I could see her whole bed clearly. When I looked through, she was stripping in front of a full-length mirror beside her bed, slowly, running her hands over her shoulders, and over her tits, and her ass, as she pulled off her shirt, and then her lacy bra, and then her pants and panties. At this point, she's fully naked, and I can see every inch of her because the mirror is facing me, and I can see her directly from the back.

Then, like it was something out of a fucking porno, she got into bed, with the bedside lamp still on, and lay out across her blankets, and started masturbating. She started slow, teasing her pink nipples between her fingers, and then running her palm across her shaved pussy, spreading her lips open, and slipping her fingers inside. I almost passed out holding my breath, I was so scared to make a sound. She started finger fucking herself, making this amazing little moans, until she came all over her hands, bucking up and down on her bed. I have no idea how my dad and her mom didn't hear it, because I definitely heard everything.

When she turned off the light, I jacked off furiously three or four times in a row, remembering the sight of her big sweet tits and her wet, shaved, tight little pussy cumming on her fingers. I fell asleep in a daze, wondering if it would be a one-off.

Turns out, it wasn't. Kacey finger fucked herself almost every night, and I watched every time. I stood on my tip toes up against that wall so much that my friends even commented on my calf muscles. That was my life for three years until I moved away for college, and it was better than any porn on earth.