After the night my mum’s boyfriend, Dirty Derek, snuck in my room and fucked me, things changed dramatically in our household. For a start, he stopped showing an interest in my mother. I thought she would be angry with me, but instead, she was really pleased.

From what I heard most nights while lying in bed, Derek was pretty brutal and kinky with my mother in the bedroom. I assumed she had gotten sick and tired of his kinky games and sexual fetishes. Also, I don’t think my mother ever liked him that much to begin with. It was evident from the start that she was only shagging him for his money.

It seemed that Mother was only too pleased that Derek had turned his attention to me. She seemed only too happy to pass the mantle to me, her slutty seventeen-year-old daughter.

It was a week after he fucked me that I saw him standing at the entrance of my bedroom once again. This time it was morning and I had just woken up. Derek stood there leaning casually against the doorframe with his arms folded. He had on a grubby string vest, a pair of tatty old socks with a hairy toe protruding from the end of one, and a pair of Y-fronts that looked like they had seen better days. Again, like before, I was horrified by how hairy he was. His entire body was matted with wiry grey hair that made him look like a bear.

My gaze dropped lower and I noticed his Y-fronts were tented at the front, propped up by a raging hard-on that must have been at least six inches in length and as thick as my forearm. I had slept naked that night and my bedclothes had rucked up, leaving the slot between my legs fully exposed. My legs were wide open, giving Derek a titillating view of my tender teen cunt.

I coughed to clear my throat and then covered myself with the bed sheets.

“Oh, don’t be like that,” he sighed in a kind tone. “We’re going out for some fun today. Just you and me.” He entered my room and stood beside my bed, squeezing the bulge at the front of his Y-fronts. “Come on, be a good girl and open those legs. Let me have a taste of that juicy fruit between your thighs.”

I really wanted to. The urge to have this dirty old man lick and suck my tender cunt was overwhelming.

“Where’s Mother? What if she catches us?” I asked.

Derek sat beside me on the bed, the springs groaning with the onslaught of his body weight, and started to pinch my toes and ankles. “She’s downstairs making breakfast. She won’t disturb us. She knows the score.”

Derek’s hands moved to my sides, pinching my outer thighs and stomach. I giggled and pushed the soles of my feet against his chest to halt his advancements, saying, “Stop it, you dirty old git.” I giggled, enjoying the feel of his clammy hands on my body.

Little did I know, in doing this I had left my buttocks gaping open, exposing my tight little arsehole for a swift invasion.

His hand didn’t need a second invitation. Before I knew what was happening, a greasy forefinger had slipped straight up my anus, all the way to the knuckle. It was a shock at first and I screeched, “Oh my God!” with fright. But then it felt weird yet wonderful and arousing, and I found myself involuntarily squirming on the bed, bucking my hips and squealing and giggling, then writhing with the heat spreading out over my body.

My body was alive with sexual sensation, so I lay on my back, opened my legs and wrapped them around Derek’s fat head, gripping him in a tight headlock and smothering his face with my juicy cunt. I thrust my hips, mashing my pussy against his stubbly face. Then I felt his tongue go to work over my crevice, his stubble tickling my nether region and heightening my arousal. I groaned as I felt exotic sensations washing over me.

I felt myself drifting off into a state of intense sexual arousal. I don’t know what Derek’s tongue was doing between my legs, but before I knew it, an orgasm was sweeping over me that nearly blew my head off. I was seeing stars for a moment. My hips bucked manically and I was grasping at the bed sheets to stop myself from bouncing off the bed. I gave out a loud sigh as I fell back to earth, regaining my composure.

Derek couldn’t resist giving my arsehole a little lick before standing up to admire my naked form.

I lay on the bed, spread-eagled, breathing heavy, my most intimate areas exposed to Derek’s avid gaze. He spent a moment leering down at me and fiddling with his cock that was now poking out of his Y-fronts. In one swift motion, he whipped his underpants down to his ankles and sat astride my face. Mounting my head, he grabbed his cock and began slapping it over my face.

His groan of delight filled the room as he sank his chunky cock into my mouth. It smelt strongly of sweat and tasted vaguely of piss, but that just served to heighten my arousal As he held the back of my head and pumped his rampant member in and out of my mouth, he gasped, “Oh yeah, that’s a prime suckhole. We’ll call this one the cum-dump as well, 'cause it’s where I’m gonna dump my load when I’m done.”

Opening my eyes, I watched his thick meat sliding in and out of my mouth. My jaw started to ache, but his filthy words made me hot. I loved the fact that he had assumed total dominance over me and was treating me like a little fuck-slut.

He was like a man possessed now with his blood up, relentless as he thrust his fat erection in my mouth over and over. “Suck it, you dirty little bitch!” he barked excitedly. “Suck that big fat fucking cock!”

I could do nothing but answer him with a helpless glug, glug, glug. I was choking, suffocating on his fat rod and my own spit.

“Oh fuck!” he snapped. “Time to dump some cum into the cum-dump!”

I looked up at him, watching his face contort into a grotesque sneer as his cock throbbed between my lips. Then my eyes widened with surprise as I felt a jet of warm spunk hit the back of my throat. He held my head still as he filled my mouth with a full load of cum, making me choke and gag with the onslaught. My cheeks bulged after the fourth spurt of liquid, the cum leaking down my chin as I struggled to swallow the thick spunk.

I was running out of air when he finally fell back onto the bed, his cock slipping from my lips. Wheezing and panting, he jumped off the bed and went to my clothes drawer. Pulling out the skimpiest two-piece string-bikini he could find, he threw it to me and said, “We’re going shopping. But you’re wearing that.”

The thought of wearing such little clothing out in public gave me an almighty thrill. I got myself showered and slipped on my bikini, ready for a day of sordid perversion with my mother’s boyfriend, Dirty Derek.

***

“Have fun, guys,” my mother shouted as we left the house, not even trying to hide her delight at spending the day alone instead of having Derek lurking around her all day making constant sexual demands.

Despite it being a very hot day, Derek wore black polyester trousers and a white button-up shirt. On his feet, he had open-toed sandals with white socks with a fat hairy big toe protruding from the end of one.

I can’t describe the thrill I felt venturing outside wearing so little clothing. My nipples and pussy, the only parts of my body that were concealed, immediately tingled with sexual delight.

As we approached the car, Derek stopped and scratched his chin. He thought for a moment then said, “It’s pension day today, isn’t it?”

“Yes,” I replied, looking confused.

“Why don’t we take the bus instead of the car,” he suggested. “Those old boys on the bus will have a treat when they see you wearing that bikini.”

I smiled widely. The thought really did turn me on.

The bus was pulling into the stop when we arrived. We had to run to get on before it pulled away. Derek waddled quickly rather than ran, with his potbelly bouncing up and down at every stride and sweat pouring down his face.

When we boarded the bus, the driver’s eyes immediately fixed onto my tits. He was delighted to see only my nipples were concealed within the skimpy top with the fleshy parts of my breasts fully exposed. His eyes never left my tits the whole time we were paying our fare.

Feeling aroused and very naughty, I pushed my chest out to give him a bit of a thrill. He went bright red with embarrassment. Stifling a giggle, I moved towards the back of the bus and sat down with Derek who was now breathing heavily.

At the next stop, there was a huge queue of pensioners waiting to get on. They started filling the bus. Everyone took a double take when they saw me, sitting at the back of the bus almost naked.

Derek’s eyes lit up. “Fucking hell. If you don't get groped today, it will be a fucking miracle," he murmured with a dirty grin on his face, fiddling absentmindedly with the bulge in his trousers. “Stand up, sweetheart,” he demanded between heavy breaths. “Let the old folk sit down.”

Feeling excited at the prospect of being groped by an old codger, I smiled and stood up before reaching for the bar above my head to steady myself.

The bus was pretty packed now with quite a few people standing as we moved off. I noticed that I was surrounded by old folk, all in close proximity to me. So when I felt something brush across my taut bottom a few seconds later, a massive smile spread across my lips. I hadn't seen anyone younger than sixty get on the bus, so I knew it was some old codger feeling me up.

The hand quickly became frantic and I stifled a gasp as it groped and squeezed my firm buttocks. Trying not to draw attention to myself, I opened my legs slightly when he pushed against my inner thighs, gasping loudly when his fingers slipped under the elastic of my bikini bottoms and rubbed along the crease of my cunt before slipping easily into my wet hole.

I could feel the tingle building in my stomach and wasn't sure I could stay quiet if I climaxed. My knees were starting to give already as I felt his bony old fingers sliding in and out of my peach slices and rubbing across my engorged clit. My hips began to gyrate gently of their own accord, and I pushed myself back onto his fingers as he slipped another one inside me. Then I felt something wet and warm prodding against my buttocks, streaking my skin with a slippery liquid. The old man had his cock out and was grinding it against my buttocks!

“Wank him!” Derek demanded in the background, again showing his dominance.

Reaching behind me, I took hold of the old man’s stubby cock. It was really quite small, much smaller than Derek’s and really thin. My dainty hand engulfed the entire shaft, leaving just the slimy head exposed.

I moved the foreskin up and down, tugging on the stiff rod, pulling it this way and that, slapping it against my back, grazing the head against my buttocks. The old man loved it. His breath was hot and heavy on the side of my face, gasping and groaning as I toyed with his little cock. His fingers were working overtime inside my bikini bottoms, pistoning in and out of my sloppy-wet cunt, finger-fucking me hard and fast.

Within less than a minute, a strangulated groan escaped the man’s throat and I felt a rope on warm goo splash against my lower back. I carried on pulling and tugging on the wizened old cock as the next jet clung to my buttocks. Then it just seemed to stop throbbing and pumping and began to dwindle in my hand. I gave it a squeeze to try to revive it, but it was spent.

Just then the bus stopped and people started to move towards the doors. The fingers were instantly withdrawn from my pussy and I felt and heard the snap of the elastic as the waistband fell back into place.

I held onto the bar above me as people pushed past to get off, my legs trembling with arousal. I glanced out of the window and saw a little old man giving me a toothless grin. He held his fingers to his nose and made a show of sniffing them. He then gave me a cheeky smile as the bus moved off.

“You fucking loved that, you dirty little whore!” snarled Derek.

Feeling turned-on and dirty, I had never been so aroused in my life.

When we arrived at the clothes store it was brimming with customers. The place was packed. I spent over an hour picking out several outfits and pairs of sexy underwear. Derek just watched me the whole time, playing with his cock every now and then and sweating like a pig. When it was time for me to try them on, he insisted that he come in the changing room too.

He joined me in the changing room. With the curtain closed, it was our own private room. Derek pulled his underpants down to his ankles, his stiff cock pointing straight at me, and watched me try on the clothes. He toyed with his cock as I tried on various outfits, stroking it gently and twiddling the drooling bell end while fondling his dangling ball-sack. He watched me with an avid leer in his eyes as I stripped off and tried on all sorts of different clothes and put on a real show.

He got ever so excited when it came to me trying on the underwear. I was stripping off completely naked and trying on all sorts of sexy lingerie, all the while posing for Derek and giving him titillating glimpses of my tight snatch. He began fisting his cock furiously, his face a picture of concentration and his tongue poking out from the corner of his mouth.

He was wanking his cock like a man possessed and tugging harshly on his sweaty ball bag as I continued to try on the underwear. As he massaged his knob, every now and then a large blob of pre-cum would form on the swollen bell end, and he would say, “Be a good girl and lick that off me helmet.”

I would do as requested and slurp the clear liquid from his drooling member. It was slippery on my tongue and had a musky, salty flavour.

It was after I’d run my tongue over Derek’s helmet for the fourth time that he began to lose his composure. “Oh, fuck, you sexy little bitch. You don’t know what you’re doing to me. I can’t hold back any longer. I can’t control myself. I’m gonna fuck the fucking life out of ya.”

At that point I slid the sexy knickers down my legs, leaving myself completely naked. I turned my back to Derek and bent over and parted my buttocks and pussy, giving a full and unhindered view of my arsehole and the inner folds of my juicy cunt.

Derek totally lost his composure. “Oh, fuck, you saucy little minx.” He sprang to his feet, stumbling with his trousers tightly wrapped around his ankles, and grabbed my thighs. He shoved his cock into me hard and fierce, showing me no mercy. I cried out in pain, but the shock sent a tremor of arousal through me.

“I’m gonna fuck the fucking cunt off ya, you teasing little bitch!” he exclaimed as he ploughed his cock in and out of my body.

The slapping sound of his thighs hitting my arse and my yelps and gasps rang out for all the shoppers outside the changing room to hear. Derek had lost it, but he didn’t take long to come.

He slipped a finger into my arse then slapped my buttocks hard, making me screech with shock and delight, and then flooded my hot little cunny with his old-man seed.

He groaned loudly with every squirt as he filled me full of goo. There was so much spunk injected into me I thought my pussy would burst.

“Fuck, that’s a hot little cunt,” he breathed as his orgasm subsided. I slipped my bikini back on and left the changing room to go pay for the goods.

When we exited the changing room, the whole shop had fallen silent. It was hard to ignore the looks of disgust and disapproval on the faces of the shoppers. They had obviously heard the noise of our fuck session emanating from the changing room. I looked down at the floor, though I could still feel their eyes burning into me.

Derek was oblivious and as happy as could be. He was holding all my new clothes, taking them to the checkout to pay for them, all the while whistling a tune.

A moment later, my shame and embarrassment could have swallowed me, as I felt Derek’s cum ooze from my vagina. I used my forefinger to pull the gusset of my bottoms to one side, allowing the flow of cum to dribble down my leg. The people behind us at the checkout were staring as think goo trickled down my leg, past my ankle and onto the floor.

I heard a woman say, “Disgusting girl.”

I’d been embarrassed and humiliated, but God it was exciting. I’d never been so turned on in all my life.