My Boyfriend's Sister

It hadn't ever been my intention to be unfaithful to Mark, it just happened that way. I could try and wriggle out of it and say that because the other person was another woman and not a man that I wasn't really being unfaithful. Man or woman though, I still went behind his back and that's what matters. It's not the first time I've been with another woman, I'd had a number of partners, both male and female, before I met Mark. Mark knows all about my past and, being a fairly typical male, claims that he finds the idea of me with another woman, extremely arousing. He's even gone as far to say that he wouldn't mind me having an 'affair' with another woman so long as I gave him a graphic, blow by blow account afterwards. I'm not entirely sure if he meant it, you can never tell with men. Even if he did mean every word I think that the fact that the woman involved was his own sister might be a little too much for him to take.

I wasn't really in any position to complain when Mark asked me if I'd mind if his sister came to live with us for the summer. She had just finished school and would be starting College in September, as a result she needed somewhere to stay until she had a place of her own sorted out. Given that Mark had just fucked my brains out then eaten me to a massive, toe curling orgasm I'd have agreed to just about anything. We had a spare room and she'd help with the rent so I really had no grounds for complaint.

Cath was 18. I hadn't seen her for a couple of years and I was stunned by the changes in her. Gone was the gangly, spotty, slightly awkward teenager who had once taken me into her confidence when she'd wanted advice on 'boyfriend matters'. Cath had developed into an assertively confident, stunningly attractive young woman with long, honey blonde hair and curves that even I, generously proportioned as I am, would have died for. We hit it off immediately and in no time at all we were firm friends. We were soon sharing confidences again, albeit of a slightly more adult nature and, I have to say, I really enjoyed her company, especially when Mark's bar job meant he was often out until the wee small hours of the morning.

Even then, nothing would have happened if it hadn't been for one of those strange concentrations of coincidence that happen every so often.

It was a Friday night. Cath was going to be going out with some friends and Mark was meant to be home fairly early. I'd planned a special evening for the two of us. Much as I liked Cath her presence had put a bit of a damper on Mark's and my sex life. Not that we'd suddenly become celibate but we had had to become a little more circumspect. That night would have been the first time in almost three weeks that we'd had the place to ourselves.

My preparations were meticulous. At about 5:30 I'd retired, wine glass in hand, to the bathroom. A long, hot soak always helped to get me in the mood. After my bath I spent a pleasant hour carelessly rubbing my favourite scented body cremé into my skin. The result was a series of small but extremely intense orgasms that, while pleasant, left me gagging for attention. Mark wasn't going to know what had hit him when he got home. I fixed my make up and spent some time selecting my most provocative underwear which I concealed below an oriental silk dressing gown which just happened to be a favourite of his. I wanted Mark to have no doubt whatsoever as to what was in store that evening. To say I was devastated when Mark called to say that he was having to work late because the late shift supervisor had called in sick was an understatement. Having already opened a bottle of wine, I decide that my only alternative was to drown my sorrows. It would have been a shame to let the rest of the bottle go to waste.

I was more than a little surprised when a little over half an hour and two glasses of wine later Cath returned. "You're home early," I remarked somewhat obviously.

"Yeah, I know," was Cath's disgruntled reply.

"Bad night?" I enquired.

"Just don't even ask," she replied. Then she noticed how I was dressed, "Not interrupting anything am I?" she asked apprehensively.

"No, unfortunately," I sighed. "Mark called to say he's having to work late." I held up the wine bottle, "Why don't you grab a glass and help me with this," I said, "then, when this one's finished there's another in the fridge."

"Cheers," replied Cath before walking through to the kitchen to get herself a glass. She returned almost instantly and flopped down beside me on the sofa. "Anything on the telly?" she asked as she held out her glass.

"Doubt it," I replied as poured for her.

Cath took a long sip of her wine and sighed. "Thanks," she said, "I needed that."

"No problem," I said lightly.

We chatted for a bit as we drank our wine. As we did Cath reached into her bag and extracted her tobacco and cigarette papers. I picked up the ashtray and my packet from beside the sofa. "You can have one of mine if you want," I said as she fumbled with the papers.

"Thanks," replied Cath, "but if it's all right with you I think I'd prefer something a little stronger." I watched as she delved into her pocket and removed a matchbox. She deftly opened it to reveal a lump of a dark brown substance. Cath looked at me enquiringly.

"I don't mind at all," I said, "Just so long as you're sharing."

"I think I can manage that," she said with a smile.

I looked on in fascination as Cath skilfully rolled the joint. "Mark probably wouldn't approve if he was here mind you." I commented.

"Mark can be so stuffy sometimes," said Cath, "I sometimes wonder how you've stuck him so long."

"Oh I don't know," I replied, "he does have his good points."

Cath laughed, "I'm sure he does," she said, "but I'm his sister so I wouldn't know about those."

We both laughed. Cath gave the end of the joint a twist then tore off a strip from the lid of her cigarette paper packet, rolled it up tightly before inserting it into the other end. She raised it to her lips and lit it, inhaling deeply. "Ahhh," she sighed as she let the strong smelling smoke escape from between her lips. "Fuck, that's good," she said before taking another long draw. She passed it to me. I inhaled deeply, savouring the strong taste as I drew the smoke into my lungs. I closed my eyes and held my breath, slowly counting to ten before exhaling. I coughed a little, I was clearly out of practice. It had been over a year since my last joint. I inhaled again and felt my body begin to relax. I took one more draw before I passed it back to Cath.

The effects of the drug combined with my sense of frustration I'd felt when my plans for evening had been thwarted. As Cath and I talked and smoked I felt a curious attraction growing. Her proximity was beginning to make me a little uncomfortable, especially as our conversation became increasingly frank.

"So?" I asked at one point, "Do you have a boyfriend at moment?"

Cath shook her head, "No," said with a sigh, "not at the moment. Actually I think I'm off guys just now. I'm having trouble finding one who's interested in me as a person. They only seem to be interested in getting inside my knickers."

I laughed, "I can understand that," I blurted, "I mean, you're very attractive and..." I stopped realising that I was just digging a bigger hole for myself.

Cath looked at me. "Am I to take it you like girls then?" she asked suggestively, her hand lightly stroking my exposed thigh.

"Well, you could say that," I said, "I've had sex with a couple of girls in the past. Nothing serious, just a bit of fun really."

"And did you enjoy it?" she asked, her hand stroking up under the hem of my dressing gown.

I felt a rising sense of excitement. "Yes," I replied, answering her questions, both the spoken and the unspoken.

"Good," she replied, "I like girls too," and then she kissed me.

I didn't hesitate, I didn't try to stop her I simply moved into her embrace and returned the kiss. Cath's breath was hot against mine. My earlier frustration rose up and demanded to be relieved. The kiss grew more passionate and almost instinctively, my hands began tugging at her clothes.

Cath removed her blouse then stood up and wriggled out of her jeans. I slipped out of my dressing gown as she sat down. Our hands explored each others' bodies as our lips pressed firmly together. Cath slipped the straps of my bra down off my shoulders. My nipples stiffened as she ran the flats of her hands over my tits. "Oh that's nice," I purred softly as she lowered her head and began to gently lick my soft globes.

I reached behind her and unhooked her bra. As it fell away I lifted my hands to her tits and began to cup and squeeze them. My fingers teased her nipples as Cath's tongue flicked lightly over mine. I moaned with pleasure as she took each nipple in turn and sucked it deep into her mouth.

She caressed my inner thigh with one hand as her mouth worked on my tits. Cath's fingers slowly inserted themselves under the flimsy material and began to stroke my soft curls. I tensed and opened my legs slightly as her fingers worked towards their target.

"Oooh, yessss!" I moaned as her fingers slipped between my moist lower lips. She slid her finger into my cunt and my muscles contracted to grip it tightly. She pulled it out and then used it to tease my nipple, coating me with my own juice. I moaned again as she moved her mouth to suck my essence from my nipple. The finger of her other hand was now in my cunt and she was soon repeating the process on the other side.

Over and over, her finger dipped into my hot wet hole then spread my juices over my tits, only to have her mouth lick and suck them clean. The feelings were deliciously dirty and I soon found myself on the brink of an orgasm. My body shook as her fingers brushed lightly over my clit. "Yes!" I breathed as I surrendered myself to the sensations.

"Nice?" asked Cath softly.

"Mmm, nice," was all I could muster in reply.

Cath removed her fingers from my cunt, giving me the chance to recover and kissed me. I could taste myself on her lips. Hungry for more I lifted her hand to my mouth and sucked her fingers between my lips, savouring the rich taste of my arousal.

Without any further delay Cath was on the floor kneeling in front of me. I wriggled my bum forward to the edge of the sofa, lifting it slightly as Cath tugged at my sodden knickers, unwrapping my hot and eager cunt. She wasted no time. Her tongue pushed between my moist lower lips and licked the length of my slit. Her tongue was soft and my body shuddered in response to its touch. Cath may have been young but she obviously had a lot of experience when it came to pleasuring another woman's pussy. She flicked her tongue lightly over my clit, sending bolts of pleasure shooting through me. I moaned my appreciation as she delicately sucked my labia into her mouth.

My hands stroked over my tits as her tongue darted in and out of my pussy. My nipples were stiff and I teased them between my fingers as Cath's tongue hungrily explored my cunt.

I felt my body begin to tingle as my arousal rose even higher. "Yes," I sighed, "oh that feels so good." Cath sucked my clit between her lips and flicked her tongue over he tip. My body responded and I began to feel the first stirrings of my impending climax. "Oh yes! Don't stop!" I moaned as Cath's tongue lapped up and down between my lower lips, tracing its path from my hot, wet hole to my clit and back again.

My body began to shake. Squeezing my tits together as Cath's tongue fanned the flames of my passion higher, I bit my lip and let the pressure grow. My body screamed for release as Cath's mouth relentlessly drove me closer and closer to my orgasm.

Finally, I could hold off no longer. "Mmmmoooh!!" I moaned as my back arched, lifting my bum off the sofa. I clutched Cath's head pushing her mouth even more firmly against my throbbing clit as the walls of my pussy contracted sending violent spasms through my womb. My head lashed from side to side as my climax held me in its grasp. Cath's tongue still flicked over my clit but now her touch was lighter, slower, more tender as she endeavoured to hold me at boiling point.

"No more! No more!" I gasped finally. Smiling, Cath reached out to me. I took her hand and joined her on the floor. She held me close as my heart pounded in my chest, my breath coming in gasps. Tenderly, she kissed me as I slowly recovered. My juices glistened on her face. "Thank you," I whispered softly in her ear.

"My pleasure," replied Cath smiling broadly.

We held each other close, kissing and caressing as my breathing and heartbeat slowly returned to normal. Our kisses gradually began to increase in intensity, my hands began to explore Cath's body. She squirmed with pleasure as my fingers ran up the inside of her legs. She sighed as my tongue traced the curve of her tits. I licked over her soft globes with a circular motion, working in from the outside until my tongue flicked over her nipples. My saliva made her skin slick and my hands slid easily over her tits as they stroked and caressed them.

I began to work my way downwards. I kissed and licked my way over Cath's flat stomach as I moved towards my destination. I slid my hands under the elastic of Cath's soaking knickers and slowly pushed them off to reveal a neatly trimmed pussy. Cath parted her legs. Her lower lips were enflamed and glistened with her moisture. I positioned myself between her slender legs and leaned forward. "Ooh," Cath sighed as I ran my tongue along the edge of one lip. I repeated the process with the other the gently slid my tongue between them. Her juices flowed from her cunt and I savoured their taste as my tongue lapped up and down her slit. Cath's body shuddered slightly as I licked over her clit before sucking it gently between my lips

The hot flavour of Cath's sex overwhelmed me. I pushed my mouth more firmly against her pussy and began to lick with increasing urgency. My tongue darted in and out of her cunt and I could feel the walls tighten in response as Cath writhed on the floor before me.

"Stop," Cath wailed, "I want to get on top." I rolled over onto my back and Cath straddled my head with her legs, her pussy hovering tantalisingly close above my face. I reached up to grab her hips. As I pulled her towards me my tongue slid between lips. Her juices flowed over my face, coating me with their warm stickiness as she ground her cunt against my mouth.

I reached up to play with her tits as my tongue danced over her clit. As I squeezed her nipples between my fingers I was rewarded with a lust filled "Yesss!"

Cath's hips began to buck. I pushed her tits firmly together and sucked her clit into my mouth. I flicked its tip with my tongue and Cath began to moan more and more loudly. "Don't stop!" She yelled, "Oh Lorna, don't stop!" Her body shook more and more violently. Each touch of my tongue made her flinch reflexively. I pressed my tongue firmly against her clit and moved it slowly from side to side, holding Cath at the peak of her climax.

Suddenly she was gone. She rolled away and lay down beside me. "Thank you," she sighed into my ear then kissed me soundly. Her tongue licked over my face, cleaning away her juices. We lay there for a while, just holding each other close, basking in the afterglow of the experience.

"Care for another drink?" I asked finally.

"Sure," she replied. "Care for another smoke?"

I nodded. Cath rolled a joint as I topped up our glasses. We drank and smoked with only the occasional contented "Mmm," to break the silence.

I was feeling light headed. My earlier orgasm, instead of satisfying my desire, left me feeling randier than ever. I watched on as Cath took one last long draw on the joint. She kissed me, releasing the richly flavoured smoke into my mouth. I drew it into my lungs then slowly exhaled it back into her mouth. The effect was intoxicating and left me highly aroused. It obviously had the same effect on Cath as our kisses became more and more passionate.

Suddenly, she broke away and gently pushed me onto my back. She swung her leg over me and, once again, her pussy was in front of my face. She lay forward and I felt her hot breath on my pussy. I flicked my tongue along her slit, heard her moan and then she began to lick mine in return.

I savoured the sensation of having my pussy eaten by Cath as I feasted on hers. My body was aflame as her tongue licked between my lips and darted into my hole. Cath ground her pussy against my hungry mouth and in response, I increased the pace of my strokes. A warm tingling feeling rose up inside me and I suddenly wanted to be on top. I wanted to ride her face as her tongue pleasured me.

Cath must have sensed my need. Without warning our positions were reversed. I was on top, grinding myself against her mouth while my tongue flicked over her clit and she was below, both of us giving and receiving as our tongues drove us inexorably towards a climax.

My body began to shake. I sucked down hard on Cath's clit. She responded by licking even harder on mine. The actions of one fed the responses of the other, building up until the sensations could no longer be contained I don't know who came first, all I can remember is moaning loudly as Cath's body shook below mine. I rolled off. Turning around, I was gathered into her arms. We held each other tight as our exhausted bodies struggled to recover.

Afterwards we each took a well needed shower. Cath went first as I tidied up the living room and then I took mine. After I dried myself off, I joined her in her room for a quick cuddle before heading off to bed.

It could only have been about twenty minutes later that Mark returned home. Far from quenching my desire, the events of the evening had left me even hungrier than ever for his cock. Mark didn't know what hit him, I literally jumped on him the moment he came into the room. He was tired but he heroically responded to my none too subtle advances. We fucked furiously. It was short and sharp and while I didn't cum, Mark quenched the fire of my desire. While Cath had erased the disappointment of earlier, Mark had provided the perfect end to the evening. With my cunt filled with Mark's hot, sticky cum, I finally fell into a deep and satisfied sleep.

Cath found a place of her own shortly after that. It's pretty close by. Funnily enough, I always seem to have an excuse to call round on those nights that Mark isn't around. Mark is really pleased that Cath and I get on so well, although he doesn't know just how well. Despite the fact that he claims he would love to hear the details if I had sex with another woman, I've never told him about Cath and me. Broad minded as he is, I don't really think he'd approve.