My father remarried when I was about 13 years old to a rather unpleasant woman with two girls of her own. The eldest of the two, Jenny, was about four years older than me (17 at the time of this story) and the youngest, Kate, was my age. Jenny was a very attractive teenager; with a slender build, long curly hair, and medium sized breasts, she was one of the more popular girls in her high school. The youngest, Kate, was also very attractive, but more petite and larger breasts. They lived in a small two story house with three bedrooms: one master, and one room for each of the girls. When my sister and I would come to visit on the weekends, we would have to sleep either on the floor or share a bed with one of our stepsisters.

I would often sleep in the same bed as Jenny, the eldest stepsister, as she had the biggest bed and was often out partying until late at night. One night, I was lying in bed with the lights off watching some late night TV, when Jenny opens the door to her room, stumbles across to her clothes dresser (where the TV was sitting), and begins rummaging through the top drawer. She was obviously still drunk from her night out on the town and was completely oblivious that I was lying in her bed. She pulled out a pair of thong panties, a large baggy t-shirt, and her shower robe, then placed them on top of the dresser. With her back to me, she unbuttoned her jeans and began pulling them down, revealing her pink thong and perfectly shaped teenage ass. I sat there staring in amazement as the sudden rush of adrenaline and surging hormones rushed blood to my cock, causing it to grow rapidly.

I had been jerking off to a picture one of Jenny's ex-boyfriends had taken where she was flashing her tits at a football game. I found the picture torn up in her trash can, and it was one of the first images I had used to jerk off to. It was covered in stains and dried cum, where I had accidentally (or purposely) shot my load all over her bare chest and face. Seeing her stripping in front of me, I hoped that she would turn around and I would get to see her bare chest, but this time, for real.

She continued undressing unaware of my presence and completely occupied watching TV. She dropped her jeans to the ground and stepped out, kicking them off to the side. Next, she crossed her arms around the front of her body, grabbed the bottom of her shirt and began to lift it up and off. I reached down subconsciously and touched my throbbing cock, which was now fully erect and jutting out the front hole of my boxers. I began rubbing the head lightly in anticipation as she reached around and began unclasping her bra. She removed it quickly and threw it on the ground next to her, turning slightly, exposing the side of her breast. She remained facing the television while she reached down, grabbed the straps of her thong with her thumbs, and pulled them down over her ass. She bent over a little as she was pulling them down to step out, exposing her pussy lips and tight looking asshole. This was the first pussy I had ever seen, and I began rubbing my engorged erection uncontrollably.

After throwing aside her panties, Jenny picked up the items she had laid on the dresser and turned around to the bed, where she was suddenly surprised to find me under the covers, staring wide-eyed at her naked body.

She froze suddenly, trying to assess the situation in her drunken state, while my gaze flashed from her perky breasts (which were larger than in the photo I had) to the thin strip of hair leading down to her pussy. She quickly turned away from me blushing, and clumsily put on her robe.

"Shit! I didn't realize you were in here," she yelled angrily.

"Sorry, I was asleep the whole time," I lied, "I didn't see anything!" She stormed out of the room while avoiding making any eye contact and locked herself in the bathroom across the hall.

I heard the shower turn on moments later and the shower curtain slide shut. I laid back in bed. The adrenaline was still in full effect and the image of her naked body still burned in my mind.

"Holy shit! I can't believe that just happened," I said to myself. I closed my eyes and started slowing stroking the shaft of my still hard cock, trying to remember every detail of her naked body. I knew Jenny usually took thirty minute showers, so I figured I had time to finish up before she came back. I grabbed the remote and turned the channel to the after-dark premium channel, which showed softcore porn after midnight. I watched a pretty cheesy scene followed by some large breasted women getting undressed in a locker room. I continued stroking my cock, watching the TV, and simultaneously trying to keep the naked image of Jenny fresh in my mind.

I must not have heard the shower turn off, because about ten minutes after Jenny had gone into the bathroom, I heard the door open.

Hearing the door I quickly regained my senses, turned the TV off, and rolled over on my side, pretending to be asleep. I still had a full, pulsing erection and a sweaty back, but I remained motionless as she walked over to the bed and slid in-between the covers on the right side with her back to me.

"I know you're awake. Sorry, I got so mad with you earlier," she said over her shoulder in a hushed tone, "you just surprised me."

"It's OK," I said with a shaky voice.

She let out a laugh and rolled over to face me, "Yea, I bet it was." I could smell the alcohol on her breath; I knew she was still a bit tipsy. She paused for a second then continued, "Was this the first time you've seen a naked girl before?"

"I've seen lots of girls on TV," I said trying to act cool, "but never up close".

"Uh huh...well, sorry about that. Let's just watch some TV and not tell anybody that it happened, OK"? I nodded my head in agreement, and she gave me a quick smile.

"Cool. Let's see what's on," she said rolling over and reaching for the remote.

Unfortunately, when she turned on the TV, the softcore porn I had been watching earlier popped up on the screen. The large breasted women were now getting fucked in a pool while a group of onlookers watched the action. As we both stared at the screen in silence, the sexual tension began to make things awkward. Also, I had rolled over on my back to face the TV, forgetting about the huge erection I still had protruding out of my boxers. The light from the TV cast an obvious shadow on the comforter, and Jenny had definitely noticed my protruding cock.

"Were you jerking off in here while I was in the shower?"

I nodded, immediately trying to conceal my now obvious erection, shoving it back into my boxers.

"You should probably go do something about that, so things don't get even weirder."

I laughed nervously then slid out from under the covers. When I stood up, my cock shot out of the hole in my boxers and stood at full attention. Jenny's eyes grew larger as she stared directly at it.

"Damn it!" I said laughing as I turned away and ran off to the bathroom in embarrassment. I sat in the bathroom going over everything that had happened in the last fifteen minutes.

I guess the embarrassment of the situation had made me lose my erection, so after about five minutes I returned to the bedroom. I was shocked to see the TV was still on the softcore porn channel and Jenny was still watching it. I slid back into bed, confused.

"Ok, I took care of it. Sorry if I made things weird." She looked over to me with sleepy eyes and smiled, "Well, now I have to take care of things".

I looked down the bed and saw the comforter around her crotch slowly bobbing up and down. I had never thought about girls being able to play with themselves. I guess they could get off just like I could. My erection had returned.

This time, she didn't say anything about the mound in the comforter where my cock was protruding. I started slowly rubbing the head, which could easily be seen through the comforter. Still no objections from Jenny, who was concentrating on watching the fucking couple on TV and not what I was doing. I started to fully stroke my cock while partially watching the porn on TV and partially watching Jenny play with herself under the covers. The shaking of the bed from my strokes must have distracted Jenny, because she glanced down the bed to where my dick was and watched me.

After a minute, with her free left hand, she lifted up the covers and stared directly at my cock. The pace of my strokes increased as she watched me. I lifted up the covers on my side with my free left hand, just following her lead, and looked over at her body. She had her night shirt pulled up to below her breasts, and her right hand was partially down the front of her panties, moving in and out. We both continued watching each other for a little while, slowly increasing our pace and breathing harder. I felt like I was going to cum at any second and spray my load all over the sheets, but she suddenly dropped the covers on her side.

With her free hand she grabbed my left arm, which was holding the covers up, and pulled it towards her, causing me roll over on my side and face her. She let go of my arm and rested it on her stomach, and started squirming around. A second later she produced a pair of thong panties from under the covers and threw them on the floor. She grabbed the back of my hand and slowly slid it down her body. We passed the small mound of hair on her pussy, which felt smooth and fluffy, and was surrounded by bumps where she had shaved some of the hair off. She slid my hand down between her legs, then stopped and put her fingers behind mine, and pressed them into her warm, moist pussy. She spread her legs wider and began to guide my fingers over her pussy; up and down and in and out. When she felt I had the pattern down, she let go of my hand, reached up and grabbed the back my head, and pulled it toward hers. I had never kissed a girl before, but it seemed to come naturally. She stuck her tongue in my mouth and played with mine for a while; I just copied everything she did and tried to mix it up a bit.

Now she had her hand behind my back and was pulling me closer to her. Waves rushed through her body causing her hips to thrust in an out. We were both on our sides now, my hand between her legs rubbing patterns in her pussy, and my cock rubbing against her thighs, my thrusts matching hers. We became slowly aware of the increasing squeaking noise caused by our movement on the large bed.

Jenny pulled her head back and said irritated, "This fucking bed is sooo fucking loud! I'm sure everyone in the house can hear us. Get up, I have an idea." She threw up the covers and slid out of bed. I quickly followed her out of bed, trying to figure out what she had planned for us next. She walked around to a chest at the foot of the bed which was about three feet high, five feet long, and two feet deep. She turned to me and pulled off her night shirt, revealing her large, firm breasts and slender body in the light of the TV. "Take those off," she said pointing to my boxers and sitting down on the chest, "and come over here." I quickly pulled down my boxers and walked over to the chest.

When I was standing directly in front of her, she shifted back a bit, put her feet up on the chest, and spread her knees apart, sitting crab style. She pulled me in closer between her legs, my cock perfectly lined up with her now wet pussy. She grabbed my cock for the first time and began stroking it rapidly and rubbing it against her pussy. As she did this, I attempted to fondle her firm breasts but kept getting distracted by the pleasure of someone else playing with my cock. When she felt my cock was rock hard enough and fully lubricated with her juices, she guided the tip of my cock into her surprisingly tight pussy hole. She reached her hands around to my ass and slowly pulled me forward. She had a look of discomfort on her face as I slid further and further in, but eventually she closed her eyes in ecstasy. She moved her hands to my sides and slowly pushed me away then pulled me back in, each time increasing the pace. My body naturally began following the motions, and soon I was pounding her pussy faster than she could control. I braced myself against the chest as I thrust faster and faster, going deeper and deeper each time. I watched Jenny's tits bounce up and down and listened to her heavy breathing.

"I'm about to cum, I whispered to Jenny through my heavy breathing. She pushed me away from her just in time, and began to stroke my cock quickly. I sprayed what seemed like a gallon of cum all over her flat stomach and tits, which dripped off her nipples and pooled in her belly button.

We rested for a minute, passionately kissing while she squeezed every last drop of cum from my balls. She bent over and kissed the head of my cock, and went to the bathroom to wash herself off. I was laying on the bed cooling off when Jenny came back into the room and started putting her clothes back on.

"OK, we have to talk about this," She said laying down on the bed next to me. "I had a lot of fun tonight, but if we want to keep doing this, we have to keep it a secret. A BIG secret. We can't tell ANYBODY about what happened or else we could be in huge trouble."

I laughed a little, "As long as we keep doing that, I promise to do anything you want."

She gave me one big kiss and laid down next to me, "I might have to take you up on that offer."

Unknown to Jenny and I, the noise of our heavy breathing had woken up Kate, the younger sister, who had been watching us fucking from the doorway the entire time. Things were about to get interesting.

To Be Continued...