After my father was made redundant and we could no longer afford the big house we used to live in, we had to move into an old disused shop with an upstairs flat. There weren’t enough bedrooms for all of us, so my bed was a mattress on the floor in a hallway at the bottom of the stairs.

I was lying on the mattress with my trousers and pants pulled down around my knees while my fourteen year-old sister Abi enthusiastically sucked my penis. She had no panties on and was squatting with her skirt tucked into her waistband. We’d put the light on so that I could see everything as I finger fucked her vagina with two fingers, which both of us were really enjoying me doing. I was a bit of a late developer, but we’d both started growing pubic hair and I’d started to leak pre-cum when I got excited, and had recently started spunking off, which Abi found very exciting.

As she was expertly sucking my penis I’d started to leak cum into her mouth, which she loved the taste of, so she soon got so excited that her vagina got really wet, then all of a sudden she must have had her first ever orgasm, as her pussy just started spurting. As soon as I felt this amazing thing happening I just had to have my mouth on her vagina, so that I could enjoy the juices she was spurting, so I swivelled my head off the mattress and underneath her leg, then glued my mouth to her vagina as she continued to spurt. Wow, it was bloody amazing!

We were both enjoying it so much that we didn’t hear the lounge door upstairs open and my father beginning to come down the stairs. Luckily he started to say something to me before he got to the turn in the stairwell that would have revealed his incestuous teenage son and daughter enthusiastically slurping vagina and sucking penis; Abi heard him and immediately stood up and scuttled out of the door into the main shop, while I hurriedly swivelled back on to the mattress and pulled the duvet over myself, my half-mast trousers and my stiff penis, pulling the duvet up with one hand while I grabbed a book I’d been reading from beside the mattress with the other.

Dad must have heard the scuttling, as he looked a bit puzzled as he came into view; he paused in the question he was asking, looking at me very oddly for some reason, then he finished his question, which was something about watching a show that I might be interested in on the TV later that evening. His teenage son innocently looked back up at him and answered the question, all the time hoping that his father wouldn’t notice his own daughter’s vaginal juices all over his son’s face and down the front of his T shirt. If Dad had come all the way down the stairs the game would have been up though, as the place smelt like a brothel :-0

With his question answered, Dad turned to go back upstairs, but he then looked back again for about twenty seconds without saying anything, but didn’t seem to be looking directly at me, which was a bit odd, then he continued on his way upstairs. Abi heard him go back into the lounge and came to the doorway from the hall looking bright red, with her skirt now pulled down to cover her naked vagina. I had managed to pull my trousers up, but hadn’t pulled my zip up. Abi was grinning at me all wrapped up in the duvet, but then suddenly her face changed and her jaw dropped as she pointed; I look down and saw that her white schoolgirl’s panties were where she’d kicked them off, right in the middle of the floor between the mattress and the bottom of the stairs where dad couldn’t have failed to notice them.

The inside gusset of Abi’s panties was facing upwards, with a very obvious darkly wet patch where Abi had oozed juices into her knickers. I’d lifted her onto the edge of the shop counter as soon as we’d walked in from school, pulling her knickers to one side to gain access to my little sister’s body, and then I’d roughly fingered and licked her, as well as opening her school blouse and lifting her little bra up to pinch and suck her little schoolgirl nipples.

Me fingering, licking her and sucking her nipples had made her so horny that she’d insisted we retire to the mattress for her to suck my penis. If the light had been off I doubt that Dad would have seen much, but the light in the hall was a strong one, as there was no window in the hall or on the stairs, so the dirty panties were illuminated and stuck out like a sore thumb as they lay there on the dark carpet.

I don’t see how Dad could not have seen Abi’s dirty knickers. He definitely knew that she was downstairs with me, as he’d called down when he heard us come in, asking how school had been. Abi had shouted back to say that it had been fine, as I’d been too busy with my mouth on her vagina. So, the question running through Dad’s mind would have been had Abi or I pulled her dirty panties off? What could the reason be for that and why was the gusset of Abi’s panties so obviously soaking wet? He must have known that Abi must be within earshot, but out of sight, with her vagina naked and uncovered. He would also have been sure that Abi wouldn’t have let me take off her knickers unless she wanted me to do it, so she must have actively agreed to their removal. Had she lifted her skirt up and asked me to remove them, or had she taken them off herself? Had his son seen his daughter’s vagina, or had she kept it hidden? I can’t imagine what Dad must have been thinking as he sat in the lounge upstairs knowing that we were downstairs, although his imagination must have been running wild about what we had been getting up to and wondering what we were doing right then!

Abi grabbed my hand and pulled me up off my mattress, then she grabbed my limp penis as it dangled outside my trousers and led me into the main shop area by it, then she pointed to the floor and I lay down. She stood, one foot either side of my head facing my feet, she bent her waist and looked down at me between her legs, saying “Dad is now upstairs wondering what’s going on down here, isn’t he?”. I nodded, “Ooooh, that feels really odd, but really dirty and exciting!” she said. She lifted her short skirt up and squatted down, placing her tight little vagina over my mouth. It was still very, very wet from her spurting and I just loved slurping those juices and slipping my tongue inside my young sister’s body. Abi enjoyed my actions for a few minutes, then she leant forward and went onto her knees, engulfing my now very erect penis in her mouth, wanking me as she slobbered and sucked and licked my penis, while I continued to slurp up her vaginal juices, reaching around her slim legs to stretch her vagina wide open with my fingers in order to gain better access. All of this soon made me shoot my spunk and I couldn’t suppress an animal grunt and long groan as my orgasm hit and my spunk began to burst from my penis.