It was, as they say, like waving a red flag to a bull...

Laura was bent over and rummaging through the dresser. It was one of my favourite positions. She was only wearing a loose, white T-shirt, which afforded me a look at her long, slender legs. My eyes traveled up the length of her smooth thighs and lingered upon her arse. It was such a tempting sight. Laura had the most luscious arse I'd ever seen — full and ripe and so immensely fuckable.

I checked myself.

I couldn't do it again. Yes, she was beautiful, young, innocent, sexy, and willing to fuck at the drop of a hat. And yes, we had done so at every opportunity this whole week. But it was far too risky now. The chances of getting caught were too high. We had to stop. I had to stop. But as Laura started pawing through the back of the drawer, she bent a little lower, and afforded me a glimpse of her puffy, tender little pussy.

And it hit me like a stroke.

"What the... ," she blurted, as I grabbed her from behind.

The poor dear hardly knew what hit her. My prick was already embedded in her tight girlish pussy before she had had a chance to realise what had happened. But like all young girls, she was adaptable. Within seconds, her body had reacted to my onslaught. Her pussy got wet, and her hips started to push back against me.

"We can't do this," she moaned, as she tried to twist around. "She'll be back any minute."

I heard her, but it didn't matter. She was right, but it didn't matter. Nothing mattered anymore. I fucked her harder. I rammed it up her with everything I had. I was lost to everything except the compulsion to stuff my cock inside her hot, tight, teen pussy.

"Oh, yes, yes, yes... ," she began to cry, as she surrendered to the sensations of her body.

She widened her legs and stood up on her tiptoes as I stepped in between her legs. I held her waist as I pushed straight up. She relaxed and pushed down upon me. I groaned as her thick, luscious lips slobbered at my shaft.

"I'll be quick, I swear," I panted. "We'll be finished before she comes home"

She started moaning and shuddering. Her hips gyrated crazily as she rammed her arse against my lap. My pelvis was almost directly beneath her, and every time she pushed down, I was almost taking her entire weight on my dick. She was so forceful I was afraid that she would snap off my dick.

But it felt too good to stop.

I slipped my hand under her T-shirt. As usual, she wore nothing underneath. It was easier that way. I was never patient enough to wait for her to shuck off her clothes, unhook her bra and slip off her panties. I couldn't stand the time in took to jump into bed or lay on the sofa. I certainly couldn't afford the time to slip on a condom. Fucking the daylights out of her was a reflex action. I was like one of Pavlov's dogs and she was the meat that made me salivate.

My hands were full of her meaty breasts at that moment. Her breasts were full and firm, like warm rubber earmuffs. I started playing with her taut little nipples. She moaned every time I rubbed her hard, bullet nipples. She gasped when I pinched them and rolled them between my thumb and index finger. She loved it. Her hips started to waver as she lost concentration. Her thighs quivered under the combined attack of my fingers and my prick.

She collapsed against me. I dropped her tits and held her by her waist. Her eyes were closed and her breathing ragged. I just concentrated on that delicious feeling of long-shafting her. My dick made slopping, sucking noises in her cunt as it churned inside her.

"I don't know how I'm going to live without this," I murmured in her ear. "You're so fucking sexy, I wanna jump your bones every time I see you."

She turned her head and looked at me with her heavy-lidded eyes. She smiled dreamily as she tried to concentrate on something other than my prick sawing through her lips.

"We can still do stuff if we don't get caught," she slurred. "It's not like, like, oh, oh..."

Her voice trailed off in series of little sighs. She closed her eyes as she started pushing back against me. Her eyebrows were knitted together as she concentrated upon riding me.

A couple of minutes later, I could tell she was close. She was losing control again. Her head was bowed. Her body was slumped against mine. She supported herself shakily on the dresser, and she would've fallen over if my arms weren't wrapped around her. A faint mewling sound came out of her cracked, parted lips. Oh yes, she was lost inside herself and so very, very close.

I slowed down. I didn't want her to come yet. I started humping her in long, slow motions, taking it out up to the knob, because sliding it back it. I counted ten heartbeats for every stroke. She was so still, so quiet in my arms that it was like she was asleep. Only her shivering, quivering torso betrayed the tension in her body.

"Do you want it, baby?" I crooned in her ear.

She nodded in response, her eyes still closed.

"I want to hear you say it, honey. Let me know what you want."

Her voice was slurred and slushy as she breathed it into my ear.

"Fuck me, please, please, fuck me until it hurts..."

I groaned as I heard those words coming from her pure, innocent mouth. It was all too much. A week ago, I would've died of shock if I heard her say those words. She'd changed so much in such a short time.

And to think — she was still only seventeen.

"What do you think you're doing?!"

I turned my head. May was standing in the doorway, her hands on her hips. For a second, I was speechless. She looked furious, and ready to bite my head off, but I couldn't help but be aroused - she was so fucking attractive when she was angry.

"What do you think it looks like? I'm fucking your sister!"

I started giving Laura a series of short, sharp thrusts. There wasn't much time before May recovered from the shock of seeing us together. My right hand slipped down her stomach to the fuzzy, peachy pussy lips. She started gasping as my fingers climbed over her greasy, engorged mound, trying to find her clit. When I found it, I started frigging it like made. Meanwhile, I pounded into her like an epileptic rabbit, desperately trying to get her off before May took those four or five steps towards us.

"Oh, oh, oh..."

If my hands hadn't been around her, Laura would've dropped to the floor. I pulled her into me as the first of her orgasms rippled through her body. She wasn't big on screaming. She whimpered in my arms as her pussy convulsed. She leaned forward on the dresser and daintily, lifted herself off my throbbing, tortured prick. She turned around and smiled weakly at her big sister.

"Hi, May. How's work?"

In the meantime, May had taken those four steps. Her hands gripped my shoulder like a banshee's talons as she pushed me aside. I tripped over the trousers that were still wrapped around my feet. I fell on the bed. A furiously beautiful May hovered above me.

Fuck, I was going to get it. I can talk my way out of most situations, but being caught fucking your fiancée's seventeen year old sister isn't most situations. I racked my brains but came up with nothing.

"Look, May, I know it looks bad from where you're standing, but..."

I trailed off. As always, the sight of her in full fury left me in awe. She was breathtaking in the way that only an Amazonian goddess can be. She was six foot tall with full breasts and flared hips, legs that stretched forever and an arse that was sculpted like the Venus di Milo. But it was her face that held me; blazing green eyes that seem the more intense by her close-cropped, jet-black hair, china-white skin and a wide, sensuous mouth that ended with an unconscious pout. Even when she was seriously pissed off, she couldn't help but exude the erotic appeal of a wanton temple prostitute.

"Oh, I guess you and Laura weren't fucking the shit out of each other? I can't believe you'd do this to me, you fucking pervert!"

"Well, you see ... it was meant to be a surprise?"

It sounded stupid when it left my mouth. It sounded increasingly worse each ominous second it hung in the air.

And then she laughed.

"Damn it, I love surprises. I'm sorry I ruined it. I was just so pissed off to see you and Laura fucking over there ... I guess I over-reacted. Can you forgive me?"

She pouted as she came closer.

"Um, yeah ... sure I can forgive you. No problem."

She stepped out of her skirt and unbuttoned her shirt. She climbed onto the bed and straddled me.

"So what's the big surprise? I hope it's something good..."

My prick was wedged in the crevice between her thighs and her panties. She grinned as she ground against it like a scratching post. I groaned and tried to think, think fast. There had to be a plausible explanation ... but it was hard to think with all the blood was pumping through my prick.

"Fuck..." I sighed.

"Excuse me?"

"Um, I wanted to practice fucking..." I elaborated. "You know, how some people practice dancing before their wedding so they'll be able to do the bridal waltz?"

"Yeah, go on..."

"I wanted to practice fucking ... to make sure our wedding night went well." I stammered. "Laura, um, Laura was kind enough to practice with me. We figured it wasn't cheating since if we kept it in the family."

"How sweet," she murmured as her rubbed herself against my tormented prick. "You knew I wanted to abstain until our wedding night, and yet you wanted to be in good shape for me. What a sweet, sensitive man you are."

May lay on top of me. She rested her arms across my chest. Her lips formed a crooked little half-smile.

"It must've been such a hard imposition for you," she said, her hips grinding against mine for emphasis. "I'm so sorry that I'm making you go through with it. But I'm so glad you got little Laura to help you keep in shape. It's such a relief, in a way. I was worried you'd go running off with some strange tart."

"I should've told you, I guess. I'm sorry to have shocked you like that." I said. I was feeling magnanimous. After all, it wasn't every day the fortuitously improbable occurred.

She sniggered.

"That's the lamest excuse I've ever heard. How stupid do you think I am?" she giggled. "Actually, I've got a confession for you, too. Laura and I concocted something special for our wedding night as well. I really shouldn't have burst in on you like that. I spoilt everything."