Pavlov's Conditioning

Author's Note: I should probably finish the series I have started before beginning new ones, but I wanted to do something incesty, so here it is... And yes, Molly's story continues and I plan to write about the other siblings, too. All characters are over the age of 18.

"Oh yeah, fuck me harder! Just like that, oh fuck, your cock is sooo good, Jimmy!"

I slowly swam to consciousness, groggy and a little disoriented. It had only been a couple of weeks since I had moved across the country from the small town of Summerset, Nevada, to start college in Trafton, Iowa. Jessica, my middle sister, was in her senior year at the women's college my mother had insisted all of her daughters go to, and she had rented an apartment for the both of us to live in.

We never had a lot of money growing up and with six kids, my mother and stepfather could only help us out so much. The apartment was just a small one-bedroom. Jessica and I each had a twin bed, crammed into opposite corners of the bedroom. The tiny living room had a couch and TV, and we fit a postage stamp-sized dining table into the kitchen area. It was actually very cozy and despite the cramped space, we got along well. I had been a little worried about living in harmony with my older, glamorous sister, but to my surprise, she welcomed me with genuine warmth.

This morning, it took me a few seconds to realize what exactly I was hearing. I hadn't even realized Jessica had brought someone home with her when she came back last night from a party.

Jessica's words had been whispered, but still very clear in our bedroom. They echoed in my head as I blinked in the early morning light coming in through the blinds. Then I focused across the narrow space between our beds and what I saw shocked me beyond belief.

A man's naked butt was pumping between my sister's outstretched legs. He was panting hard and all of the muscles in his back and ass and legs were rippling with strength. I had never seen a naked, male body before and my eyes widened as my brain raced to process what was happening.

"Oh God, it's so good! Fuck me just like that, I'm going to come all over your cock, Jimmy! I'm going to come, I'm going to--"

The man clamped his hand over Jessica's mouth as she let out a muffled shriek, her legs shaking around his thrusting hips. He groaned long and low as he rammed forward in a final, deep lunge, straining as he held himself still.

After a few seconds, he lowered himself down and I could tell they were kissing, a really lewd, messy kiss with noisy smacking and moaning. I lay there in my own bed, just a few feet away, my vagina swollen and damp and so hot under the covers. I had never felt like this physically before, but above all, I was reeling mentally.

When I was 6, my widowed mother remarried and she brought my two sisters and I to live with my stepfather's family. It was kind of a Brady Bunch situation; my mother with three daughters and my stepfather with three sons. At the time, Connor, my oldest stepbrother, was 17 and a senior in high school. Robbie was 16 and Sean, 14. My oldest sister Delilah was 12, Jessica was 10, and then came me, the baby.

I don't remember my birth father at all, but Delilah says he wasn't much different than our stepfather. Very Catholic, very conservative, and very stern.

Our household was as strict as you could get. We were all homeschooled and weren't really allowed to do anything fun, which led to a lot of fights growing up. I remember hearing Connor and my stepfather roaring at each other about the curfews and rules against parties and dating.

That lasted a few months before Connor went off to college, way on the other side of the country. I hardly saw him again--there was a lot of resentment and bad feelings between him and his father, and he didn't come home much.

Things weren't a lot calmer when he had gone, though. All of my siblings went through the same rebellion and unhappiness with my stepfather's rules. The fights continued and, if you can believe it, got even worse with my sisters. They would scream at my stepfather that he wasn't their real dad and he would yell back that while they were under his roof, they would obey his rules. By the time I was a teenager and my siblings had all gone to college far, far away, I was sick of the fighting.

So I was the good girl. I never snuck out of the house at night to go to parties, and I never had any secret boyfriends. I wore my conservative blouses and skirts and hardly looked anyone in the eye because I was so shy. My stepfather stopped blustering and yelling and would pinch my cheek and tell me how happy I made him. My mother was my best friend, and while she and I cooked dinner every night, we would discuss my schoolwork and my hopes and dreams, and really, I wasn't very lonely at all.

I begged my parents to let me go to the small, conservative college near our small town in Nevada. I wouldn't have felt so strange or out of place there and I could have continued living my quiet life at home. But my mother was adamant--she wanted all of her daughters to have the same, wonderful college experience she had.

Little did she know that only two weeks after I arrived, I would be subjected to the sight of my sister having sex right in front of me.

The long kiss ended and Jessica giggled. I heard Jimmy whisper, "Did we wake up your sister?" He turned to look back but I snapped my eyes shut so that they would think I was still sleeping.

"Mm, don't worry, babe. She's fine."

After a while, Jimmy got up and left. When my sister returned to the room from a quick shower, she sat on the edge of my bed.

"Molly," she said, "I know you're awake."

I peeked over the edge of the sheets with wide eyes.

Jessica huffed out a laugh at my expression. "Don't tell me you really are just as good as Ma always says?"

"I've never--" I said, my voice coming out high and squeaky. "I mean, Jessica! We're not even supposed to date until after college and you're having sex?! Are you going to marry that guy?"

At this, my sister laughed until tears were streaming down her face. I sat up, embarrassed and a little affronted.

"Why are you laughing?"

"Because I would never marry Jimmy, Molly! What are you even thinking?"

"I'm thinking you're having premarital sex, which is a sin, Jessica." I hissed the last words in a fierce whisper. I shouldn't have to tell her this--after all, our stepfather had expounded on this very subject multiple times at the dinner table, along with harsh recriminations for the "slutty" clothes my sisters wore.

"Oh, Molly. You really are just a baby, aren't you?" She said this without any judgment or malice and she smiled at me affectionately while patting my thigh. Despite this, I still felt dumb, naive, and confused.

My face must have shown how I felt because Jessica sighed and continued, "Listen, little sister. Dad was wrong, okay? It's not a sin. It's a lot of fun, actually, if you can find the right guy."

I paused before saying, "Like the 'One'?"

"Nooo, not the 'One'." She had to stifle another laugh at that. "No, I mean a guy who knows how to use his cock and make you feel good. You know what I mean?"

I shook my head slowly, not having a clue, and she stared at me strangely for a minute.

"Wait," she finally said. "Molly, do you even know how sex works?"

"Jessica!" I huffed, rolling my eyes and crossing my arms across my chest. "Of course I know what sex is!"

"Oh my God! You have no idea, don't you?" She was laughing again and shaking her head.

"Stop laughing! What you're doing is wrong. I'm the one doing the right thing here!"

"Oh Molly. Molly Molly Molly." Jessica wiped the tears from her eyes and then, in a strangely tender gesture, she leaned forward and cupped my face with both hands. "I'm going to have to show you what you're missing."

I protested, but she just smiled mysteriously and we didn't say anything more on the subject that day. Her subtle campaign of corruption had just started.

Jessica didn't push me. She never even really talked about it after that first morning. She just kept bringing guys home from parties, knowing that the constant sex show she put on was enough to subvert my morals without even having to go through the effort of verbalizing anything.

My sister was really beautiful, with her long, red, curly hair and her sensual curves. She had great tits too, although she often said mine were even better. But I didn't show them off like she did, in her low-cut tops and push-up bras. Sometimes, I would just stare at her deep, plump cleavage until she would catch me and I'd blush and she'd laugh. It was no problem for her to pick up guys--they were practically salivating at her feet everywhere she went--school, her job at the coffee shop, parties.

She wasn't shy about throwing off the covers and being naked in front of me. I got really used to seeing her body and, after a while, it didn't make me so embarrassed. In fact, I began to look forward to seeing her strut around the apartment totally bare. She was so confident and naturally sexy; I envied her.

It was the same with all of the bare cock. They seemed so gross at first, all hairy at the base and dusky purple or red when they were hard. But Jessica loved them so much, no matter what size or shape, and I began to look at them differently. She would give those college boys blow jobs as they sat on the edge of her bed, at the perfect angle for me to see her lick and suck them off while moaning in ecstatic bliss.

I took a psychology class that first semester and they taught the concept of classical conditioning and what Pavlov did with his dogs. One night, while we sat on the couch watching a documentary about Alaskan huskies, I suddenly blurted out, "I think I must be like one of Pavlov's dogs. All of your obvious enjoyment of cock and sex is training my brain to want it, too."

She hummed in thought. "But Pavlov rewarded his dogs for good behavior, right? It's not like I reward you with a treat every time you watch me fuck someone."

"Well, no... But the reward is how I feel, isn't it?"

She smiled then, wickedly and gleefully. "Oh really? What are you saying, Molly? Do you feel good when you watch me have sex?"

"Yes... a little." A predictable blush spread over my face.

Jessica had turned to face me on the couch, folding her hands under her chin and giving me a pleading look. "Well, tell me! What feels good?"

"You already know, Jessica..." I said, turning away to hide my embarrassment.

"No, I don't know. Tell me. Where does it feel good?"

"Down there!" I whispered, at that time still unable to use the naughty words that Jessica used so often. The word "pussy" was emblazoned in my mind, but I couldn't bring myself to push it past my lips.

"Yeeeah?" She drew out the word. "Does your pussy feel all hot and achy? Does it get wet and swollen? Does it make you want to touch yourself?"

I nodded shame-facedly. "But it's a sin, Jessica. We're not supposed to."

"Just forget all of that. Focus on what feels good, Molly. Life is short, why not have fun while we're at it?"

"Uhh, because we'll go to hell?"

Jessica shrugged. "I don't know if I believe in hell." When she saw my face, she hurriedly added, "Now don't you go telling our parents I said that! I don't want to come home during the holidays to a bunch of lectures."

"I won't," I sighed. "But I really just don't understand what the point of it all is, Jessica. I mean, it feels kind of warm and tingly, and it's nice, but it's not anything to risk going to hell over."

Jessica didn't say anything more. She just gave me a look that I had come to know meant trouble.

A couple of days later, I woke up to the familiar sounds of kissing and whispering. I stretched under the covers, pointing my toes and yawning before I opened my eyes. The scene my sister had set that morning was a little different than usual, and seeing it made me instantly wet.

This time, the boy, who I recognized as one of her coffee shop coworkers--a tall, cute college student named Matt, was sitting up against the headboard with his legs spread wide to accommodate my sister in between them.

She was sitting with her back against his chest, with her own legs spread out, her knees bent over his thighs. This put her pussy right in my full view. It was the first time I had really seen it like that--up until then, she had always been getting fucked or was on her knees sucking cock.

Now, I could see it all--her pink, puffy lips, the shadowed entrance, the shining moisture covering all of it. Matt was pulling those lower lips apart while she pinched her nipples.

"Fuck, this is so hot," he said, staring down at her most private place, exposed in the most obscene way possible.

"Yeah, you like seeing my wet pussy, Matt?" Jessica asked in a breathy whisper. "I'm going to show you what I do when I can't find a boy to fuck me."

Matt scoffed. "Yeah, right. Like you ever have trouble finding cock, Jessica." He nuzzled into her neck, and I watched as his tongue flicked her ear.

Jessica moaned before saying, "Stop distracting me. I'm trying to tell you how I like to make myself come."

"Okay, fine. How do you like to make yourself come?"

"Well first, I like to get myself nice and wet." Jessica stuck her fingers in her mouth and gave them a coat of saliva. "Usually, I'm wet enough already, but sometimes it's nice to suck on my fingers and feel naughty." She drew them out of her mouth slowly and Matt groaned.

"Fuck, you're so goddamn hot."

Jessica ignored him. She was looking straight at me now. "Then, I like to just rub all around my pussy. I like to feel how swollen I can get, how wet I am."

My heart pounding, I watched with avid attention. As stealthily as possible, I slipped my hand between my thighs and under the band of my panties, cupping my sex. I was so wet, practically dripping, and it wasn't hard to slick my fingers through my folds, exploring them just like Jessica did, mirroring her movements.

"Then, I stick my fingers in my pussy, like this." She slid her two middle fingers deep inside. "Fuck, that feels good."

She worked her hand in and out like that for a minute, her eyes hooded and boring into me.

I widened my legs and followed her example, sucking in a breath as I burrowed my fingers into my tight hole.

"Oh yeah, it feels so good, Matt. I love fucking myself with my fingers because I can curl them up and there's this spot--" She broke off in a low moan.

I was too shy to moan, but when I copied her movement, rubbing up against the front wall of my pussy, my jaw dropped open and my eyes rolled back.

"Oh my fucking God," Matt breathed. "This is driving me crazy!" I could tell he was stroking himself behind Jessica's back, and my face turned hot when I saw that he wasn't looking down at Jessica anymore, his eyes were trained straight on me.

"Then I rub my clit, just like this," Jessica said. She drew her finger up and over her little bud while she spread herself with her other hand, showing me exactly where it was. "Do you see how it sticks out a little? When I touch it, I go crazy!"

Her fingers made small circles around her clit and when I did the same, my legs automatically spread even wider under the covers. Holy mother of God, it felt amazing! We stayed like that for a few minutes as she continued to circle her clit slowly, sometimes dipping her fingers inside to bring out more of her honey. I repeated all of her movements, a delicious pleasure filling me and making me just as crazy as Matt.

"Oh yeah, that's good, oh fuck!" All of a sudden, Jessica's hand became a blur between her white thighs as she frigged herself fast and hard.

"Fuck, Matt, pinch my nipples, pinch them hard, I'm going to come, I'm going to come!"

Matt obediently moved his hands up to her breasts, pinching and pulling at her nipples so hard that it looked almost painful, but Jessica only encouraged him more. I watched in awe as the orgasm took over my sister.

"Fuck yes, Matt! Harder! Oh fuck!" I had come to know what Jessica looked like when she came, with her mouth open and her eyes hazy and almost crossed. Seeing her like that brought me to the edge as well, my hand working faster and faster and my chest heaving. The tingling and pressure became overwhelming as my pussy flooded with even more moisture. An insistent throbbing began low in my core and I panted hard as I rubbed furiously between my legs.

Jessica flopped back against Matt, her orgasm spent. He had waited long enough by that point. He pushed Jessica forward onto her hands and knees, and then he fucked her hard from behind, grunting like an animal and slamming his hips into hers so hard the bed scooted a few inches across the floor.

I watched in a haze as I continued to rub myself, the first orgasm of my life spinning upwards and outwards, spreading over my body in throbbing waves of unbelievable pleasure. "Oh my God!" I whispered, trembling all over just as Matt finished, his voice joining Jessica's in a chorus of moans and groans.

The room filled with the sound of heavy breathing as I floated in a plane of sensual discovery, completely awed by my experience, my hand clenched tight between my trembling thighs. I finally understood why Jessica did what she did. I no longer wondered why anyone would tempt the fires of hell for sexual gratification--it was completely and utterly irresistible.

After catching his breath, Matt sat back on his heels and looked me in the eye, smiling. "Well, Molly? When are you going to start joining in the fun?"

He and my sister laughed when I just pulled the sheet up over my head, too embarrassed to face them.

That was definitely the turning point. There were a few more instances when I held back, but watching my sister get fucked always made me so hot that I ended up with my hand between my thighs anyway. So I stopped trying to resist, and I masturbated all the time after that.

Jessica continued to bring boys home and I continued to peek over the top of my covers to watch. I was a fairly light sleeper and often was in bed way before Jessica came home from her dates or bar-hopping. Because of this, I wore ear plugs and rarely woke up whenever she came back with her conquest of the night. So my education more often happened in the morning, because Jessica never let a boy leave her bed without one more round after waking up.

It was obvious she really loved sex. There were lots of boys--from the other college in town, from the coffee shop, from the bars she would go out to at night. I saw Jimmy a lot; he seemed to be a favorite, and he really got off on me watching.

Sometimes, as he fucked Jessica from behind, he would insist that they face me so he could see how my hand moved under the covers between my legs.

"Are you touching yourself, Molly? Are you going to make your virgin pussy come? You love watching your sister get fucked, don't you?" he would say.

And I would bite back my moans and then shiver and shake while my orgasm took over. Jimmy loved it, and I guess Jessica did, too, because they often came at the same time as I did.

Somehow, Jessica and I (and I assume the boy) always made it to class or work on time. Once, the debauchery ended so late that I didn't even have a chance to do more than throw on my clothes before running off to class. I worried all through the lecture that everyone around me could smell my soaked panties. I couldn't understand it, but that thought made me even wetter than normal.

School flew by and before I knew it, the winter holidays had arrived, and Jessica and I flew back home together. Delilah picked us up from the Reno airport; she had driven up from LA to spend the winter break with us. We hugged for a long time at the pick-up area, and I wondered what people thought when they saw us; three young, red-haired women embracing in giddy joy.