Mum, dad and I were enjoying another of our hot threesomes when we heard the car pull up in the drive.
"That'll be Karen and Lesley," my father said, moving across the patio to meet his sisters, his hard cock throbbing in his hand.
"Oh boy," I said, looking up from where I had been hungrily devouring mum's pussy for the last fifteen minutes, "things will get even hotter now."
"Don't stop, darling," my mother remonstrated with me, reaching out a hand and grabbing hold of my head and pulling me back towards her hot steaming cunt, "you haven't finished with me yet."
"I'll never finish with you, mum," I smiled at her as I lowered my head and resumed running my tongue along the groove between her two soft cunt lips. As my tongue found the hard nubbin of mum's clit and I started to go to town on it, my two aunts appeared on the patio, dressed in tight skimpy tops and shorts that enhanced their tits and the firm round cheeks of their asses.
"Well," said my aunt Karen, slipping off her top so that her big tits swung free, "looks like we were just in time."
"Hi, girls," my mother said, inbetween squeals of delight as my tongue worked its magic on her, "why don't you take those clothes off and join in the fun?"
"We intend to," said my aunt Lesley, quickly following her sister in removing her top. The two women, who looked nowhere near the fact they were both in their fifties, also dropped their shorts to join the rest of us in the nude. Out of the corner of my eye, I was able to see my two aunts fall to their knees in front of my father who stood before his sisters to have his cock and balls sucked.
Aunt Karen didn't waste a second, she quickly took her brother's morning wood into her mouth and began sucking like a thing demented while my aunt Lesley went to work on my father's balls. Dad's eyes rolled in his head, he loved being blowjobbed and to have his two sexy sisters going down on him at once was paradise for him. I was looking forward to sucking my father's cock later too, and have him suck me, but for now I had other things to do.
"Here, mum," I said, withdrawing my tongue from her pussy, now thoroughly lubricated by my tongue, "let's sixty-nine."
Mum didn't need any encouragement, I climbed onto the sun lounge alongside her and we mounted each other while a short distance away, dad's grunts and groans of pleasure grew louder as his sisters upped the tempo. Mum and I were ascending a higher level of horniness too now as her head came down on my cock while I resumed licking her cunt. We were so engrossed with what we were doing that we almost forgot the others were there, that is until I felt a hand start to caress my bare arse.
"Wow, Karen," I heard my aunt Lesley say, breathing huskily, "our nephew certainly has a cute sexy arse."
"Yeah," said my aunt Karen and then, to my father, "you must be very proud of him."
"Oh, I am," said my father, his voice full of pride and lust as I placed my mother on her hands and knees and spat some spit onto my hand and worked it into her cunt as I stood behind her. I then peeled back my foreskin as far as I could and moved in while my father and aunts drew round to watch me fuck my mother.
As I entered mum from behind, I felt an immense feeling of privelege and honour sweep over me at being allowed to fuck the hole from which I had entered the world nearly thirty years ago and to know that my father and aunts were watching. Karen and Lesley were playing with their cunts with their fingers while dad stood back and masturbated as he watched his son fuck his wife.
"That's it son," dad said, "give it to her hard, she likes all that."
Talk about stating the bleeding obvious, I laughed to myself, anybody would think this was the first time I had fucked my mother. It had all begun more than ten years ago on my eighteenth birthday when mum and dad invited me to join them in the family sex sessions as I was then old enough to be considered a consenting adult. We'd gone out to dinner to celebrate my coming of age and mum had flirted with me throughout the evening while dad egged her on. When we got home, I was feeling as horny as fuck and when mum suggested we went up to the bedroom I was not going to turn down the prospect of an exciting finish to the evening.
Once inside, dad plonked himself in an armchair while mum kissed me hard on the lips, an act which gave me an instant hard-on. Dad was watching closely and fondling the bulge in his pants while mum continued to flirt with me, reaching down to rub the bulge that was now tenting out my own pants. It was one of the best feelings I had ever had as mum slowly started unbuttoning my shirt, pulling it out of my pants and letting the garment slip across my shoulders and drop to the floor. The point of no return had been reached and, to make it easier for mum, I unzipped my belt and pants and let them fall to the floor too. I stepped out of them and stood there in my white briefs which felt like they were going to split in two, my cock was so hard.