Younger Sister Becomes My Mistress

Younger Sister Becomes My Mistress

By Susan Greenway

[This story features incest, and includes scenes involving defecation and urination, as well as significant disciplining. If you prefer not to deal with that, read no further. All characters are over 18.]

When my sister Karen came to live with me after she graduated from college, I figured it would be nice to have her around the house. I'm a writer with plenty of work, almost all of which I do in my office within my apartment. Karen had been a math major; that enabled her to get a job with a well-regarded systems developer. She had asked if she could stay with me as I have a large place and she wanted to save some money until she saw how her job turned out.

She's four years younger than I am but looks older than her age. There's some family resemblance but she's red-haired, nicely proportioned, and stands about 5-6. I guessed that she had about a 36B chest, which turned out to be right when I had a chance to check one of her bras she left in the bathroom.

I was between girlfriends and did date once in a while. Karen never had problems having male admirers in college, probably because of her bubbly personality and overall attractiveness. She appeared to manage them all successfully and was not attached to any of them now.

I made dinner for us the day she arrived. It was something relatively simple, some pasta with caramelized onions and a salad. I took out a nice Tavel for a light wine. She seemed to like it and complimented me, noting that she never remembered me cooking anything while we were growing up.

"It was something I needed to know if I were going to enjoy living here and being home for work a lot of the time," I replied brightly.

"You obviously are a quick study," she smiled.

Before we sat down, I took her in my arms, hugged her tightly, and then kissed her softly on the lips.

"I could get used to that pretty easily," she grinned at me, so I kissed her again and we stayed entwined for a while.

She asked me to come with her to see how she had set up her room. When I followed her, I saw that she had managed to hang up some prints she liked and had organized her dressing table. I was doing well enough that I could let her use a bedroom with a dressing area containing the closet.

She gave me a dreamy-eyed look that invited close contact. I took her in my arms again and she melted into me.

"I could get used to this, too," she observed into my ear.

I began to unbutton her crisp white blouse and she nodded that I should keep going. When I slipped it off her shoulders, I efficiently unzipped her skirt and slowly helped her step out of it. Karen was wearing a nice lilac-colored bra and panty set; she proceeded to unhook her bra, releasing those charming tits.

She moved toward me and unbuttoned my shirt and took it off for me. Then she unbuckled my belt, unzipped my fly, and had me step out of my trousers. I pulled my tee over my head and decided to move this along by taking down my boxers and placing them on the chair next to us.

We lay down on her bed and I had her lift her middle so I could slip her panties down. I was surprised that she had not shaved but had a well-trimmed red bush that I found most enticing.

Karen lay back on her bed and spread her legs invitingly. I moved between them and began to lick her lightly as her folds seemed to open and become wetter. It was clear that this was turning her on. I also felt my own sex organ grow larger, harder, and more insistent.

By now, my tongue had curled and started to press into her vaginal opening. I occasionally gave her clit, which had grown to match my cock, a light lick. She seemed to be getting wetter and hotter, very quickly, too.

I did ask her if she was on the pill and if she wanted this to happen.

Her face looked as determined as any woman's I had ever seen.

"Yes, Jack," she said. "I didn't spend my time at college protecting my virginity," she laughed.

With that, she reached up and gently grasped my hard cock and guided it into her charming pink pussy. She was definitely warm because I felt the heat when I was inside her. I pressed in slowly and she began moving her midsection in rhythm.

It turned out, much to my surprise although that just shows how out of it I was, that Karen knew a lot about how to have sex. She guided my hand under her ass and pulled it toward her rear opening. When I started to place my finger at her anal star, she helped me press it softly and slowly inside her back hole.

This really put her in motion, and I was incredibly fired up myself by the strong reaction she was showing to having my cock in her cunt and my finger in her ass. I could tell by her soft moans and excitement that she was about to orgasm, and it was all I could do to keep from cumming myself.

Karen must have sensed that because she snapped, "You hold off cumming until I give you permission."

This did surprise me a little, but it did make me summon that extra effort to keep a lid on my excitement.

After we fucked some more, and I liked it more and more, I asked her, "Miss Karen, is it all right for me to cum yet?"

"Jack, do it now, please!" she virtually ordered me, and I obeyed, thrusting hard and feeling myself spurt on and on deep inside her vagina.

We held each other, kissed some more, and she said quietly but firmly that she wanted me to lick her down there now.

I'd not done that very much with my girlfriends before. They tended to want to head into the bathroom to take care of the flow resulting from their juices and my spurting.

But now I moved back between her legs and sucked the combined vaginal juices and my cum. It was surprising how good it tasted. I said to myself that I could get used to this.

"How long does it take you to get ready again?" Karen posited to me seemingly offhandedly.

"Oh, not too long," I answered coolly, "maybe a half hour or so."

"You'd better be ready in a half hour," she snapped with a tight smile. Then she started to lift herself from the bed, which I took her hand to help her complete. She held my hand as I walked her to the bathroom. I was surprised yet again when she told me to come in with her. I had never had a girl want me to see her pee and clean her cunt out before, so this both amazed and fascinated me.

When we went into the spacious bathroom, she told me to lie down on my back in the tub. I felt I had to do what she said, not just because she had just let me fuck her without my having to prevail on her for permission. I did remember that steel in her voice, however, when she told me not to cum without her permission.

I lay down in the tub, which was a bit cold. Karen stepped in, placed her legs on either side of me and moved up so she was squatting right over her face. Even with my licking to clean her, her cunt was dripping onto me. It went into my open mouth, and I liked the taste. But I wasn't sure I would like what was going to come out of her next.

It didn't take long coming either. Suddenly, a powerful stream of pee burst from her urethra and was well-aimed at my mouth.

"I want you to swallow, Jack," she said in that firm voice I was now becoming accustomed to.

So, I did. It was hot and salty but didn't taste all that awful. It was hard for me to believe that she had just arrived and was already relieving herself...in my mouth!

Finally, the stream slowed, tailed off, and ended with a few drops.

"Lick me clean up there," came the next command from the woman who had been my kid sister but was sounding more like my dominant mistress.

I hadn't run into a dominant girlfriend before. Karen clearly was used to getting men to do what she wanted. I licked her and again enjoyed the taste of her pussy and even the traces of her urine.

When I finished, she told me to keep my mouth open and this time, I didn't want to think about what might be coming next.

"Miss Karen," I found myself saying, "I've never done this before."

"You are to receive a great gift," she explained. "I expect you to receive it gratefully," she added, with the unspoken admonition that I would not be happy at all if I didn't do exactly what she ordered me to do.

I saw her cute little anal star start to pooch out and open. Then the light, brown-colored tip became visible as it slowly moved into my sight and now was about to emerge from her rectum. It was not a huge movement, but I didn't know that then. It did smell, and it moved closer as it slid out of her asshole.

It came nearer and nearer to my open mouth and then it went right in, and I took in as much as I could, with it then falling on my face. I must have been quite a sight with her bowel movement in my open mouth and a few inches of it plastered on my face.

"No, you don't need to swallow, Jack," she said in a warm tone as she complimented me for taking so much of her poo into my mouth. She reached for some toilet paper and carefully wrapped it around the part of her log that was on my face and managed to extract what was inside my mouth and get that into the paper, too. Then she flipped it into the toilet next to the tub.

I could feel that there was some residue smeared on my face and she said I looked like I had a brown mustache.

"Jack, now please lick me clean back there," she ordered sweetly.

I could only do what she said. I was now starting to wonder if she had planned all along to become my domme. Her poo didn't taste horrible, just acrid, and smelly. For whatever reason, I was actually turned on by the idea of becoming her submissive.

After all, I thought, she was pretty, bright, and was totally able to take control of a situation. I was wondering whether this would have happened if I had suggested at the start that it might be a bad idea. But my cock was doing the thinking for me, so I fell right into her plan.

After I finished licking her clean again, we both got dressed, after I had washed off my face. We had dinner and Karen was sweetness and light.

"I'm glad my big brother is so good in bed," she exulted. "There can be a lot more of that."

Karen and I watched some TV after supper. I said at about 9:30 that I was tired. She smiled and asked if I would be nice enough to sleep in her bed with her. I figured that this was something she wanted to make her feel at home and at rest in this new place, so I said, "Sure, Karen."

She kept smiling but said, "It needs to be 'Miss Karen,' Jack," she added briskly.

"Yes, Miss Karen," I responded, totally enthralled, and answering without thinking, which, of course, was just what she wanted me to say.

We each got into our pajamas, although I had usually slept in a tee and my boxers. Karen told me that we would sleep in the nude, so I took off my p.j.'s and she did too. When we got into bed and under the covers, I held her tightly and we kissed.

It was really nice, and I was growing to feel very warm toward her. She was lying on her back and spread her legs and summoned me with her little finger.

"You know what I want," she whispered.

"Inside?" I asked.

"Yes, silly, I want that cock right inside me where I can keep track of it," she replied crisply.

This sounded more and more like she was taking control. I was mostly amazed at how good I felt at being placed under her control.

Once again, we made love. It was great. I felt we were very well matched in every way. We were ready to cum at about the same moment. This time, Karen inserted her finger into my bottom-hole. I didn't have any hang-ups about it, although no girlfriend had ever done that.

I liked her very soft fingers caressing my balls and then slowly but insistently invading my anus. I hoped I was clean. That made me realize that I was probably thinking like girls do: they want their boyfriends to think they are scrupulously clean, both their cunts and their assholes.

I'd never had to think about that before. As her finger penetrated my anal ring, I began thinking about what it would be like, would I be embarrassed, if she felt something in there.

It didn't take long for me to find out, because her finger touched what was the tip of an incipient bowel movement.

"I think some little boy will need to make a doody soon," she giggled. "Ask me for permission to make your doody, Jack."

Again, I didn't even give it a thought before I responded to avoid feeling more embarrassed.

"Miss Karen, may I go and make my doody, please?" I heard myself asking like some subservient guy or maybe a guy for whom she was babysitting.

"I think we'll let you do that, Jackie," she answered coolly. We got up out of bed and went back to the bathroom. Unbeknownst to me, Karen had apparently placed a wooden child's potty in the room next to the toilet. I saw it and felt sick. This was becoming all too clear what she had in mind.

"Jackie," she said slowly but firmly, using the diminutive name, "you are going to start sitting on that potty there to do your business," she explained, as if I were a child.

It was so well planned, I later thought, that I never thought of saying no. I don't know what would have happened.

"Do I have to use that, Miss Karen?" I asked, playing along with calling her what she had told me to call her.

"Why, yes, Jackie, you do," she answered calmly, as if this should be the most obvious thing in the world to me. "You're just learning to do exactly what Miss Karen tells you to do."

"Yes, Miss Karen," I found myself saying, "thank you."

"You're a good boy, Jackie," she said warmly.

She watched me pee and then, yes, make my doody. She told me that that was the word I needed to use. I soon found out that if I didn't do what she said, she would not hesitate to correct me.

Correction involved my going across her skirted lap for a spanking, or later, getting up on the bed on all fours, when she would use her thin cane to sting my bottom. Correction was not just physical: if I didn't say things the way she told me to say them, she would say that I was being demoted a level, which meant I had to ask instead for permission to "wee-wee" or "plop-plop."

More changes in my most intimate routines followed. Karen told me that I would now be wearing panties under my trousers. And I would have to sit down to pee, like a girl.

Even though it was obvious to me that I was agreeing each time to become more submissive to her, I found myself doing it. She did keep wanting me to sleep with her and to have sex with her. Often, now, she was on top. I liked making love with her, feeling her nice breasts, and orally pleasing her between her legs. She only peed or shat on me every so often.

When I did something that displeased her, she just said, "Jackie, you've just earned a naughty mark." At the end of the week, I found out what that meant when she sat me down and recited all of my offenses which had earned a naughty mark. She kept a little book where she had written them all down each day.

Depending on how many naughty marks she had awarded me, I was either spanked or caned. I really didn't like being caned because the thin cane stung a lot, left red stripes on my bottom, and made me afraid every time she was standing there with it in her pretty hand.

I was becoming very much in love with Karen. I knew it was all wrong but that didn't matter. I loved being able to make love to her so often. The panties began to feel very comfortable when I was wearing them. I wasn't even worried about someone else discovering that I had them on.

Karen gave me a pair of black leather panties with a hole in the front. She grinned and told me to put them on for our Friday meeting when she would recite my naughty marks and correct me for them. I put them on and found out they fit but were quite tight. I was wearing just these panties for our meeting when she told me that I wasn't wearing them correctly.

I looked confused. She said very calmly that my penis needed to go through the hole. I obeyed her and became embarrassed and red-faced when I saw that it was becoming erect and thus sticking blatantly out of the hole. She was holding a little soft whip in her hand, and she laid it on my erection.

"You see, Jackie," she explained, as if I were a child or a young teenager, "if you are very naughty, I might have to use this on your little thing. But I'm sure you will keep being a good boy for me." She smiled broadly at me. I kept getting more naughty marks because I would forget to spray the bathroom after I had a bowel movement, excuse me, made my doody, or she might find a stain in my panties. I also didn't always remember to call her Miss Karen. That seemed to peeve her the most.

"You've had plenty of time to get used to that, Jackie," she said sternly. "I'm going to have to award you two naughty marks from now on if you forget that again."

These weekly sessions now inevitably preceded my being caned by Karen. I guess I should call her Miss Karen even when I'm writing this. She makes me carry the little notebook so I can give it to her when she says I've been naughty. She very ceremoniously makes an entry in the book but doesn't show it to me. Later I look at it and it says something like: "Jackie had a doody stain in his panties. One naughty mark."

She might also make a little drawing of a frowning face next to that, with a red check mark.

I never got used to receiving a caning, though. I found myself screaming because it really hurt. I did find her incredibly sexy when she was wearing heels and a flannel skirt, sometimes with sheer hose, when she caned me. She reminded me of the young, strict female teachers I had had in school.

One day, Karen came home a little early, at 3:00 P.M., and told me to help her get ready, because she had invited three of her close friends to come over for tea. We prepared the teapot and set the table. She had brought some little cakes and pastries which I set out on a nice dish. Then she held out a pink apron which she said I would wear during their visit and when I brought out their tea.

I winced but managed to say, "Of course, Miss Karen." She grinned and said, "I'm so happy you said that, Jackie, I do love you so much."

Then she looked at me straight in the eye.

"Jackie," she said crisply, "I know you will behave correctly and not embarrass me in front of my friends. This is still a little new for you, but you have been learning very quickly. I'm not trying to frighten you, but I don't want to have to correct you in front of them. It would reflect more on me than on you, but you don't want me to have to take your trousers and panties down for a caning, do you?"

My face had become very red, and I could only say, "No, Miss Karen, I will be a good boy."

I didn't fully realize it had happened, but at that moment, I was hers forever.