"Joe, please don't cum in me!" pleaded my sister.

She had reason to be concerned as I had managed to stuff about two inches of my dick into her pussy. Her was shapely ass was sticking high in the air providing me easy access. There was little she could do about it as she was bent over on her knees, her face held down on the floor by my left hand while my right hand guided my dick's progress. Sis was naked except for a skimpy blue silk robe that provided her pussy no protection from me as I penetrated her. I was as naked as my dick.

"Joe! I'm serious. I'm ovulating. You'll get me pregnant!"

"Then stop wriggling! All that shaking around could make me shoot at any minute."

Sis went fetal. She went limp as a rag doll. Not that struggling wouldn't do her any good. I had a good foot of height and at least a hundred pounds of muscle on her.

The foot of height had come in a year ago and while I was suddenly taller than her Sis still was able to dominate my stick figure frame. Only with the muscle that had come from months of weight training was I able to fight back. You'd think Sis would have noticed that her "baby" brother wasn't easy picking anymore, but she had dominated me all our life and I guess it didn't occur to her that I would grow up eventually. Now it was payback time.

"You can't knock me up, you just can't!"

I ignored her pleadings. I had no interest in impregnating Sis or even of fucking her. I was just going to push my ten inch dick all the way inside her, and then pull it out. Sis was far from a virgin so no harm would be done.

It was talking some effort, though. It was pretty clear that she never had a dick my size inside her, or even seen one as large as mine. I really did have a big dick... Ten inches long with a head that was five inches in circumference. Yeah, I know a lot of guys say that, but it really was true with me, and it's not always a blessing. You'd be surprised how many girls I have scared off in my life. On the other hand, the others are really, really into it.

I think Sis would have fallen into the scared off category, but I had no intention of giving her any choice. Still, I needed some lubrication. I wasn't going to get up to get some KY jelly. That left only her pussy juices. She was going to need some warning up.

"Sis, take off your robe," I commanded.

"What? No! Why?"

"To get access to your tits," I said reasonably, "I need to get some pussy juices flowing."

Sis whimpered and pulled her robe tighter against herself. Sis has very sensitive nipples. I've caught her numerous times rubbing them while she was watching something sexy on her soaps.

"Sis..." I said in a warning tone of voice.

"I'm not cooperating, you bastard."

"Sis, either I feel you up, or I get some lube by cumming into you." I twitched my dick inside her to drive home the point. Instantly, Sis untied her robe while I pulled it off her.

I tried to remember just what Sis liked to do to her tits. I had a good view that morning but I was distracted. After just a few minutes of trial and error, I had her gasping and my dick's progress down her pussy got easier.

An objective observer seeing my ass rise and fall as I worked my dick inside my sister's pussy while I pinched and rubbed her nipples would conclude that I was fucking her. But I swear that I was just moving my dick enough to push it in as I opened up what must have been virgin territory.

Still, I had never been inside a girl bare back and the difference was incredible. I'm sure Sis had never been fucked by a bare dick either. I don't know what difference it was making, but judging by her moaning I think she liked it.

I had to admit, it was getting harder not to shoot off inside her. Especially, when I felt her pussy squeeze my dick. She must have had an orgasm!

"Sis, if you're going to cum, let me know. We don't want to have an accident here." Sis started sobbing quietly barely audible over the slap of my balls against her ass. I was starting to make progress.

The relative silence was broken by the sound of Mom's door opening. Shit! I had forgotten all about her!

"Mom!" Sis wailed desperately.

"Mom, tell Sis to get out of my room," I yelled. If Mom thought we were just squabbling, it was unlikely she would come into my room to referee. Sure enough, Mom didn't even break her stride.

"Kids, work it out for yourself!" Mom yelled back, "You're teenagers for goodness sake. I'm going to be in the hot tub and I don't want to be disturbed." The last part was said with long pauses between the words to underline how serious she was.

Mom went down the stairs and we could clearly hear the door to the sauna room open and closed. Sis had plenty of time to yell out that I was fucking her, but she was too busy sobbing.

"Sis, yell for Mom again and I will cum inside you." I twitched my dick again. I took her two whimpers as a sign she understood and resumed pushing my dick into her and fondling her tits. Sis said nothing until I bottomed out against her cervix.

"Okay, Joe, you're got your revenge. Pull out of me now," ordered Sis.

And, I do mean ordered. She said it in that bossy older sister voice she used whenever Mom left her in charge. I previously had had every intention of pulling out, but I wasn't going to do it as if I were following her orders.

Besides, I still had about a quarter inch to go before I was all the way inside. I started pushing my dick in for the final stretch.

"Joe! Stop! It's in far enough!"

"Quiet, I'll let you know when I'm done," I said as my dick pushed against the entrance to her womb. I had only done this once before, push my dick all the way in. God it had felt good to be completely inside, but judging by the way the girl had screamed it must have hurt like hell.

I was mortified before, but this time it would serve Sis right. Slowly, I pushed in some more.

"Why are you doing this?" Sis whimpered.

Now that just made me angry. She knew perfectly why.

"Payback, Sis," I said, "Remember this morning?"

"That was a joke," said Sis rather lamely. That almost made me angry enough to cum inside her. It would serve the bitch right to get knocked up.

I had woken up this morning on my stomach with a feeling like I needed to take the biggest dump of my life. But when I rolled over I had a different sensation. Something like when the doctor asks me to cough but far more intense. My hand went to my anus and sure enough there was a dildo sticking out it!

"Good morning, dear brother," said my sister in a sing-song voice that I had learned from my earliest years to fear. She only used it when she had just put her annoying little brother, namely me, in his place.

"Jesus Christ!" I rolled over. My erection was not just a normal piss-boner. This was the real thing from the dildo!

"Language, baby brother..." began Sis, but trailed off as she took in the size of the cock. Her eyebrows nearly disappeared into her bangs as her eyes grew wide. It was an expression that I had seen many times.

I have to say it was a bit surreal seeing that expression on my sister.

Sis was a looker, no doubt about it. At five foot two strawberry blond with a pert nose, green eyes, heart shaped ass and 38D tits, most of my friends would have voted her hottest girl in high school if not for all time.

To me she was my older sister and mortal enemy. Today was just the culmination of years of conflict. And just when I thought I had finally gotten the upper hand.

I was trying to pull the dildo out. It wasn't as any thicker than my thumb, thank God, but almost all six inches of it were up my ass and I couldn't get a good enough grip on the base. The lubricant she had used was making it impossible.

"Push out like you would a bowel movement," Sis said. Then she giggled.

It was galling to take her advice, but it did seem to work. After a dozen or so pushes, I had gotten about an inch of the dildo out of my ass. I fell back on the bed exhausted by my efforts. To my horror my dick felt like it was about to spew. Sis looked on smugly, but I noticed that her eyes never left my dick. And her fingers had never left her nipples as she tweaked them under her robe.

After a few minutes rest, I lay on my back and attempted to pull the dildo out. To my disgust, the only method that worked was to ease it out a little, push it back in, and ease it out some more. It was coming out, but I was essentially fucking my own ass!

It was slow work. I was covered in sweat by the end. It must have been fifteen minutes of effort at least. But Sis just stood there her eyes never leaving my dick.

I tried not to cum. I really did. But I couldn't concentrate on pulling out the dildo and not cumming at the same time. Before I was able to completely eject it, my dick spewed out its load.

Never had I blown such a load. A wave of pleasure over took my body as well as embarrassment. Seriously, it felt like my dick would never stop spewing out arcs of cum. One actually cleared the bed startling Sis into taking a step back.

Unfortunately, she wasn't too startled to forget to whip her phone out of her robe pocket and snap a picture of me cumming with a dildo still stuck up my ass. I was even still gripping the dildo. Out of context, you could think I was deliberately fucking myself with it. If it got out there would be no end to the hell I would suffer.

"What the fuck did you do that for?" I screamed. It had to be Sis who stuck it up my ass. She just stood there frantically typing into her phone. Hopefully, she was just emailing to herself and not the whole school. I should have gone up, taken the phone away from her and throttled her, but I only had the strength to remove the dildo from my ass and collapse back on to my bed.

"Now we're even, baby brother."

Shit. Six months ago, I had managed to take my own candid snap shot of her masturbating with what looked like the very same dildo that had just been up my ass. I didn't really blackmail her, so much as I demanded that she back off with the whole big sister attitude. Well, that and doing my laundry. And my share of the household chores when Mom wasn't looking.

Her photo was so much worse than mine that she had gone beyond getting even. I was now her slave. Sis's eyes blazed with triumph and scorn. Yet, her eyes where still on my only slightly shrunken dick. Her still open robe gave a tantalizing glimpse at her big tits.

"Kids! Breakfast. I know its Saturday, but I still want you up," shouted Mom as she climbed the stairs. Sis immediately put away her phone, closed her robe and shot off for her bedroom. I just barely had time to throw the dildo under my bed and through a sheet over me.

"Get up now, Joey," said Mom as she glared at me from the door. I can't believe she still calls me Joey.

"Yeah, Joey, get up" said Sis. I have to take "Joey" from Mom, but I never before had let Sis call me Joey without retorting in kind. Sis's triumphantly held up her phone to kill any retort I might have made.

"All right, all right. Give a guy some privacy." We really weren't that shy about family nudity, but my dick was not completely soft and there were cum stains all over my bed spread. Shit, I might have to wash them myself. I was a little old to be leaving cum stains in my sheets like I had the mother of all wet dreams.

A few minutes later I joined Mom and Sis at the breakfast table. I had dressed to go out. Only the fact that Mom made such a big deal about breakfast kept me from rushing out the door. Sis gave me fake sounding greeting. She was pretty pleased with herself.

Mom gave me a more sincere greeting wishing me good morning and wrapped her arms around me giving me a vigorous hug. She had been doing that a lot lately. Usually, it embarrassed me, but this time I really need it and hugged back.

"Oh, you're so big now," said Mom affectionally rubbing my head which she could barely reach, "You're really the man of the house, now." Sis mimed gagging with her spoon behind Mom's back. Mom released me and told me to sit down and eat. I had to sit down very carefully so as to not aggravate my sore ass much to Sis's amusement.

Sis and I were pretty uncommunicative, even to Mom's attempts at starting a conversation. Of course, that was pretty typical.

Mom finished breakfast leaving us to clean up the dishes. I was about to follow her when I heard a sarcastic cough from Sis. Damn, I could no longer blackmail her into doing my share of the household tours. I walked up to the sink, but Sis just sat there at the table smiling smugly.

"Come on, Sis, we're even now."

"You wish."

"Hey, what you did for me was a lot worse than what I did to you," I said trying to be reasonable. Sis's grin grew wider.

"Exactly," said Sis, "You so don't want the picture of you with a dildo up your ass to get out. I could live down my picture, but you'd be dildo-boy for life."

"You were anxious enough to keep me happy before," I said weakly as I felt the ground shift from under my feet.

"It would be a bit embarrassing. It might cost me being head cheerleader. But I don't have some good-girl reputation to uphold. Or some misguided sense of modesty."

It was common knowledge that the cheerleading squad was a group of sluts for the football team. First string was reputed to be able to have sex on demand from any of them except for the head cheerleader. Second string took them out on fuck dates according to some sort of rotation system. There were rumors that they even showered with the team after practice. I knew this, knew that Sis was a cheerleader, but somehow I had never connected the two in my gut.

"I should have known that I couldn't blackmail a whore," I said bitterly.

"Slut, little brother.," corrected Sis, "I've never charged anyone. And a slut is just a girl who sleeps around but not with you. And I'll thank you to watch your language around me."

"But you stuck a dildo up my ass!"

"I was tired of being your slave! And I wasn't thrilled with the prospect of the entire school knowing what I looked like naked."

"I just asked you to do a few chores. It's not like I demanded sex from you."

"That's true, you didn't," said Sis blandly. I swear she sounded a little insulted.

I had nothing to say to that, so I washed the dishes. Sis continued to sit at the table enjoying watching my drudgery. As I was standing in one place, my ass didn't hurt so much. But when I tried to leave the kitchen after finishing the dishes it was hard not to walk stiffly.

"Still sore, Joey?" Leave it to Sis to add insult to injury.

"How did you do it?" I demanded. Not that I was in any position to make demands, but Sis was bursting to tell me.

"Oh, I slipped you one of Mom's sleeping pills. Once you were out, I took a jar of KY jelly and began to slowly push it up your ass."

"You bitch!"

"Oh, you enjoyed it. You were moaning constantly in your sleep. I think you even came," said Sis as she enjoyed the horrified look on my face, "It wasn't easy, though. I think it must have taken me an hour or so. I would push it in, take it out a little and push it in some more. Of course, I expect it to go up your ass much faster in the future."

"You wouldn't dare!"

"You will do as I say or you'll be known as the biggest faggot in school. I own you know, Joey!"

I couldn't take anymore. I stormed out of the kitchen and out the door. Sis actually tried to grab my arm to stop me, but I threw her off effortlessly. It was five blocks before I slowed done enough to think.

I was never much of a thinker, but I was desperate to get out of Sis's trap. I realized several things.

One was that I was now much bigger than Sis. I needed to stop thinking of her as the big sister who so easily bullied me when I was little. Nowadays, I could toss her around like a rag doll.

The second was that while Sis had a damaging digital photo of me, she wasn't all that computer savvy. She knew enough not to leave it on her phone, but she certainly emailed it to herself. And I because I had set up her computer in the first place, I had complete administrative privileges on it. I could kill that photo whenever I wanted to.

Third, I was going to release my photo. Yeah, Sis could live it down on school, but she wouldn't want Mom to see it, not if she didn't want her life to become a living hell. I was through with being Mr. Nice Guy.

I hurried home as fast as my ass would let me. The more my anus burned with it violation, the more I longed to revenge myself on Sis. The problem was I couldn't think of anything bad enough. I would have to give that more thought.

I quietly slipped back inside the house and crept up the stairs. Mom still seemed to be in her room, but Sis was not in hers. Then I noticed that my door was ajar and peeked inside. To my amazement there was Sis in her blue robe, and nothing else, bending down looking for something under my bed.

The little slut must want her dildo back, I thought darkly. I just stood there watching as Sis ass jutted out from her short robe. An evil plan took form in my brain. If Sis was going to violate me with a dildo up my ass, then my big dick up her pussy would be the perfect revenge.

But things hadn't gone exactly to plan.

I wasn't expecting Sis to enjoy me sticking my dick into her, but it did seem to increase her humiliation. Still, I wanted to repay Sis a little for my sore ass. I lifted up her ass a little and aimed so that I could jam my dick all the way into her cervix. It was hard work pushing it in that final distance. It was even harder work now to keep from cumming right inside her.

"What are you doing? It hurts," whined Sis.

"Just a little farther... farther... there," I said as I felt my pubic hair against her luscious ass. I was in all the way for only the second time in my life. I was a little disappointed. Sis was only moaning a little. The last girl I did this to was screaming bloody murder at this point.

"Pull out, please, now!" gasped Sis, "I'll do whatever you want. I'll delete that stupid picture. Just pull out."

Well, I had had my fun. Even if Sis had second thoughts after I pulled out, I could easily force her down again. Yeah, it was shitty to basically threaten to rape her, but that photo could ruin the rest of my life. If she didn't want to get burned, she shouldn't have played with fire.

As I pulled out again, Sis gasped. I had to give her credit, she was being pretty stoic with the pain. I couldn't pull out fast for fear of losing control, so I gently eased out of her.

I didn't have a chance to pull out her womb when Sis lost control.

At first, It felt like her pussy squeezing my dick again. I was amazed. Sis was enjoying this! I stopped to ride it out. But it didn't go away. The squeezing turned into contractions and it literally felt like her pussy was milking my cock. And my cock was ready to spew my cum right into her womb. If she was really ovulating, there would be no question that she would get knocked up.

"Sis, stop that! I'm going to cum."

"I can't stop," she moaned, "Pull it out now!"

I tried, I really did. But it felt like her pussy had a death grip on my disk. Her pussy muscles rippled, massaging my dick. This was the best fuck of my life, and my own sister was giving it to me! Unprotected.

"I'm cumming!" I cried out. And I did. Jets and jets of sperm streamed out my dick into her waiting womb looking for an egg waiting to be fertilized. It felt like my dick just couldn't stop spewing. I had never had an orgasm last as long as this one.

Sis cried out her orgasm, as I felt her pussy squeeze the last drops of cum. Her cum lasted awhile too, and I was beginning to worry that I would never be able to get my dick out of her pussy. A timeless moment later, her pussy released my dick and I collapsed on the floor. Sis remained kneeling on the floor crying while my cum leaked from her pussy. The rest was no doubt impregnating her.