"So what does it feel like when you put your cock in your mother's cunt?" I jumped a mile as my father appeared from behind me.
"I...I...I thought you were with Tess." I stammered.
"She's currently resting," my father laughed, "as they say in theatrical circles."
"Worn her out have you?" I chuckled. "I'm surprised you lasted this long."
"You'd be surprised how long and how often your mother and I fuck each other; she does love to a cock between her legs. I thought the two of you looked as though you were meant to fuck each other. I would have been in there like a shot but, with this overpowering urge for sex I have, your sister was too much to pass up on. She's quite a little sex goddess and once we started she became insatiable for my cock. I think you'd both enjoy yourselves, incestuously fucking each other. Happy Christmas, Son." And with that Dad walked passed me and casually pushed the head of his hard cock into Mum's eagerly waiting pussy.
Mum gasped as Dad's prick penetrated her soaking wet crack. "Oh Ben, that's fantastic." She shrieked.
"Think again honey." Dad gave a dirty laugh as he reached his full depth.
"Oh Dave, I was expecting our son's cock." She groaned as Dad began to thrust in and out of her eager body. "Oh god, what the hell; a cock is a cock and I need to cum again; fuck mmmeeeeeeee!"
I stood and watched open mouthed as I saw my parents copulating wildly for the first time in my life, most of me wishing that my cock was the one to make my mother ass gyrate so frenziedly; another part of my mind was pumping blood into my prick and making me hornier that before. Unable to stand the sight of my parents in full lustful intercourse any longer without jerking off, I turned and almost ran to my parent's bedroom.
Tess was stark naked on Mum and Dad's big bed, her legs wide open and her pussy dribbling with Dad's last ejaculation. She was rubbing her fingers between her pussy lips and then licking them clean with low moans of pleasure, swallowing our father's sperm with obvious relish.
"Got room for any more in there?" I chuckled. "Or has Dad filled his little girl's pussy to overflowing?"
Tess jumped, startled by my voice, her eyes opened and her gaze went straight to my groin and my throbbing erection. "Oh sweetie, I've got room for plenty more, but Daddy seems to have left me." Her voice was husky with hunger for more cock.
I walked over to the side of the bed and sat down, my hands reaching for her exciting breasts. "He came to see how Mum and I were getting it on and then couldn't resist Mum's cunt when she displayed it so wantonly. He pushed me out of the way and stuck his cock in before I had a chance of another repeat performance. They're at it like rabbits in my bed right now."
"So, are you going to fuck me now?" She playfully slapped my hand away. "You look prepared with your erection already so hard." She caught hold of my firm dick and began to run her hand along the full eight inches, gradually going lower until her hand was able to cup and hold my scrotum with its heavy balls, full again with my semen and ready to discharge into a suitable vessel, given the right stimulus.
My sister was providing me with just such a stimulus; she had raised herself on her elbows and was leaning into my lap and avidly sucking the head of my cock with loud vocal accompaniment. I watched the back of her bobbing head for a few minutes, before I put my hand under her chin and stopped her. "You're about to get a load of cum Sis," I whispered, "Do you want me to cum in your mouth or your pussy?"
"Oh," she lifted her head up, "Cum in my pussy. Daddy has left enough room even after cumming three times in my cunt!"
I spun round and quickly lay between her parted thighs; moving up until the saliva covered cock head was pushing against the engorged lips of her labia. I slowly entered her slippery tunnel, pressing further forward and deeper into her hot wet depths. "You can go faster, baby." Tess said softly, "I won't break and I do love a fast fuck. I want to feel your spunk exploding into my womb; wet and thick and hot!"
My sister was no longer the sullen antagonistic twin I had become used to before this day; she was now a fully-fledged cum-slut eager to take her father's and brother's cum in an orgy of incestuous fucking. "Then get ready darling," I grunted as I increased the speed of my thrusts, feeling her tight cunt gripping me firmly along the whole of my dick, squeezing me with the determined intent of making me explode my load of semen into her.
It worked. I shot a massive load of semen deep into my sister's impassioned body as she arched her back up off the bed and reached the first of three orgasms, matching the three jets of spunk I deposited deep inside her. I smiled as I thought of my millions of sperm fighting to impregnate her fertile eggs; she would look totally gorgeous when she was pregnant.
We slumped back onto the bed, our bodies exhausted by our emotional sexual arousal and the highs of our mutual climaxes. Tess held me snugly in her arms and kissed my cheek. "That was a million times better than I ever expected." She giggled. "I feel as though you could have just made me pregnant; I feel wonderful with your cock in me."
"So why did you always treat me like a leper then?" I didn't want to break the spell, but I needed to know. "I thought you really hated me."
"I didn't hate you sweetie," She purred, "I was actually so frustrated because I loved you and found you so attractive I just wanted to jump into bed with you and get you to fuck me. I didn't know how you would react if I came onto you and told you exactly how I felt, so I thought the best thing was to keep you at a distance."
"Oh god, so much time wasted." I moaned. "I love you Sis. I've wanted to tell you for ages, but I thought you found me abhorrent."
"Oh no, I won't let you go again. This is the best Christmas present I could have wished for; my own family fuck machine." She was crying softly as I kissed her neck and nibbled her ear. "I just love you inside me, your prick felt enormous when you pushed it in me; I don't want you to take it out of me, ever."
"I hope I'll be able to cope with your nymphomaniac tendencies; a fuck machine is for life, not just for Christmas." Misquoting the popular saying made her giggle.
"Well life is still going on, and you're still hard, so I'd love you to get this fuck machine working again." Tess squeezed her cunt walls around my cock and sent shivers all along my stiff dick. In answer to her request I lifted my hips up, letting my cock slide almost out of her pussy, before I slammed it back up into her eager body; my pelvis pressed hard against hers to ensure that I was fully embedded in her luscious body. As I bottomed out in her cunt she arched her back and her eyes were wide from the shock; "Fuuuuuuck," she screamed.
Each subsequent thrust ended the same way and she gasped with delight at every total invasion of her juicy tight channel. We continued to fuck for longer the second time before we both climaxed, screaming in unison, and collapsed in a sweaty heap of intertwined limbs. "I hope the fuck machine was adequate?" I gasped as I inert on her luscious sweaty body.
"Mind blowing," Tess murmured softly, "Abso...fuckingly...lutely." She closed her eyes and almost immediately slipped into a light sleep, drained emotionally by her massive orgasms.
Tess was still half asleep and holding me tightly when Mum walked into her bedroom. "Okay, lovebirds, time to let Mummy in on the action." I opened my eyes to find Mum standing by the side of the bed, still wearing her thigh-high stockings and high heels, although she now had several trickles of either Dad's or my semen (maybe both) running from her red swollen pussy lips down the inside of both thighs to add to her wanton look.
"Where's Dad?" I asked sleepily.
"Your father is out cold on your bed. He's just had two more orgasms and passed out. You know it must be the Christmas spirit but he hasn't been so attentive to my needs for ages." She lay down beside me and simply started to stroke Tess's and my bodies without thinking. Tess moaned as Mum played with her, caressing her pussy lips and rubbing her fingers in Tess's juices that were now intermingled with my copious deposits of semen. She put her fingers in her mouth and lewdly licked them clean. "My god, but you taste good together. I always knew, despite your mutual antipathy, that you'd finish up screwing each other." She resumed her teasing and when her fingers were totally coated again she offered them to her daughter. "There, darling, suck Mummy's fingers and see how good your brother's spunk tastes when it's mixed with your cum."
Tess avidly swallowed all the cum mixture Mum fed her; then lay back on the bed with a contented sigh. "Mummy, I wanted Ben to give me a baby, but Daddy was the first to put his dick in me and he never pulled out before he shot his load; you don't mind do you?"
"Of course not sweetie," Mum smiled, "But don't worry about Daddy, he had a vasectomy five years ago, so he goes bareback with every woman he fucks; Ben's is the first potent seed that's been deposited in your womb, so if you get pregnant it will be his. I'm hoping Ben's already impregnated me when he pumped me full with his seed earlier in the lounge. If we're right and he has knocked us up we can bring our babies up as twins!" She smiled at both of us, "God, I love fucking and now I've got a young stud who needs a mummy-slut to take his cum."
"Well if you're his mummy-slut, what the hell am I?"
I laughed, "You're my baby sister-slut that I want full of my semen every day."
"Every day?" Tess's eyes lit up. "I hope you can keep that promise."
"Oh believe me he can." Mum breathed softly. "After his performances earlier I can testify to his stamina."
