Female Volunteers Required

"I think we just need a couple of minutes more," Phoebe insisted, flicking the vibrator up a notch. "Number?"

"Oh fuck, eight! Please, I don't think I can take much more," Sam begged, as the buzzing got louder, changing from a low rumbling to a fierce waspy buzz as her greedy clit throbbed hotly, her body desperate for blessed relief of orgasm now.

"Oh yes, you're awfully wet now, aren't you? These cute little knickers are soaked through," Phoebe purred, sliding a finger over the damp cotton and Sam shuddered hotly as she felt it trace the swollen contours of her labia.

"Yes, oh fuck, yes!" Sam wailed, as Phoebe's fingertip flicked across her throbbing clit.

"Let's have a little look and see just how wet you are, shall we?" Phoebe said, as she hooked her finger beneath the damp gusset and hooked it aside revealing the little triangular tuft of fiery-red pubic hair and fleshy pink lips of Sam's naked pussy, engorged and glistening under the soft lights.

"Please, please," Sam squealed, her chest heaving as she felt Phoebe drew the angrily buzzing vibrator along her bare lips. Without her panties, the sensations were so much more intense and she quickly felt her body quickly pushed to boiling point as she felt Phoebe press the vibrator against the little pink bud of her clit, holding it there despite Sam's desperate wriggling until she simply couldn't take any more.

"Oh fuck, I'm coming, I'm coming!" she squealed as she experienced one of the most intense orgasms of her life, the waves of pleasure sweeping over her for what seemed like minutes, leaving her breathless and disoriented.

"Good, good," she heard Phoebe say distantly, as she felt the doctor briefly unfasten her ankles and slip off her knickers, tossing the damp scrap of red-and-white cotton onto the little pile of her clothes. Off to her left, she could hear Abby moaning too, and she twisted her head to one side and watched her friend through half-open eyes. Like Sam, she was strapped down tightly and naked apart from a small pair of pink knickers.

She'd never seem Abby topless before and studied her now, admiring her smooth, flawless skin, well-tanned except for two triangular pale patches over her small boobs, evidence of many evenings spent sunbathing on the dorm roof in her bikini top.

As she watched, Jana hooked a pale finger beneath Abby's pink knickers, deftly hooking them to one side. Unlike Sam's, Abby's pussy was shaved and she had a clear view as Jana ran the vibrator along her friend's pinkly naked lips producing a series of loud, guttural moans. She'd been quiet for several minutes, as if denying the powerful sensations caused by Jana, but the feeling of the vibrator against her nakedness seemed to cause her to surrender to the pleasure, her petite body wracked by a series of loud sobbing gasps as she twisted and writhed, her ankles and wrists straining against the tight straps.

"Now?" Jana said, in her harsh, heavily-accented English, her face impassive.

"Nine! Oh fuck, nine!" Abby gasped, her eyes squeezed shut, her body covered in a fine sheen of sweat as Jana's expert fingers brought her to the verge of orgasm.

"Good," Jana said coolly, ticking a box on her notepad.

Sam knew she perhaps shouldn't be watching this deeply intimate moment, but she just couldn't look away. She felt her own body resonate with her friends, watching closely as Abby's young body twisted and jerked, her wrists and ankles straining against the straps, all her muscles tensing, her breathing reduced to a series of harsh staccato yelps which echoed off the bare walls.

"Fuck, oh fuck, fuck, yes!" she cried as she came, and Sam watched as her young body arched against the chair, her wrists and ankles straining tightly against her bonds.

Meanwhile, Jana's pale pink lips curled into a thin smile as she flicked off the vibrator and made some more notes on her pad.

A wet noise brought Sam's attention back to her own tormentor and lifting her head she watched as Phoebe squirted a generous amount of lube onto a thick, purple dildo. She watched the woman wrap her fingers around the toy, sliding up them up and down as if she was stroking a man's cock, and slowly spreading the lube along the thick shaft until it glistened wetly. It had some kind of harness attached to it and Sam realised with a sudden sense of shock that it was a 'strap on', something she'd heard about but had never seen for real.

"Um, I think I'd like to stop now," Sam said, watching as Phoebe bent over, stepping into the harness, drawing it up over her smart black trousers and pulling it tight around her waist.

"But you're such a, what's-the-word, lively test subject, and we do so need to gather some data on this new strap-on prototype," Phoebe said with a cheeky grin as she crouched down next to Sam, using the buttons on the side of the chair to once again adjust Sam's position. "Besides we've still got plenty of time before your hour's up."

"Oh fuck, wait," Sam whimpered, shifting uncomfortably as she felt the chair shift beneath her, her legs drawn even further apart despite her struggling. They were folding now and being drawn back, so that her knees were level with her breasts, her thighs spread wantonly. At the same time, her arms were stretched out to the sides and looking to her left, she could see Abby was being put in the same gynaecological position; her arms outstretched too, their fingers nearly touching.

With her body still tightly strapped, she could only watch helplessly as the doctor positioned herself between her wantonly spread thighs, unable to draw her eyes away from the odd yet strangely arousing sight of the thick, well-lubricated shaft gently swaying between the woman's legs.

"There, well I hardly think we need any additional lubrication, do we?" Phoebe said with an amused chuckle, seemingly enjoying Sam's discomfort as she slowly ran an oily thumb along Sam's labia, still sticky from her earlier orgasm, gently spreading the inflamed petals of her sex, exposing the moist, candyfloss-pink inner lips.

Sam held her breath as she watched the woman grasp the dildo in her fist and slowly ease the fat, slick shaft back and forth along the groove of her sex.

"Now this is the new eight-inch prototype for the Stallion strap-on range," Phoebe explained, and Sam heard herself whimper as she drew the blunt end slowly up and down her engorged lips. Sam could only watch helplessly as Phoebe used her fingers to press the blunt, bulbous end against the little puckered hole of her defenceless vagina.

"Fuck, it's big! Oh, fuck, slowly!" she gasped as she felt the tip of the bulbous head force its way inside her tight little hole. It was a while since she'd had penetrative sex and the dildo felt thicker than her ex-boyfriend's dick, a little longer too. Sam groaned half in pleasure, half in pain as she felt the solid silicone prise her lips apart.

"Fuck, oh fuck!" she moaned, as the doctor started to ease the first inch of the strap-on inside, her tight pussy stretching to accommodate its generous girth, then slowly back out, her lips clinging to the fat shaft.

Sam groaned, the sensations triggering a memory of what it was like to be with her ex-boyfriend. Although she didn't always cum, there was still something about the crude sensation of being held down and penetrated with a lovely stiff cock that her body seemed hard-wired to enjoy, and as Phoebe eased another solid inch inside here, she felt her body betraying her, quickly surrendering to the crude, earthy pleasure.

Unlike her ex-boyfriend, Phoebe was patient and attentive, taking her time slowly easing the oily shaft a little deeper on each thrust, until she could feel the slick shaft smoothly pumping in and out of her velvety depths and she was panting rhythmically, loving the delicious friction, feeling the pressure in her body begin to build once more.

Straining her neck muscles, Sam could only watch and groan as the doctor fucked her (there was no other word for it), her slim hips moving fluidly, just like a man's, her hands grasping the tops of Sam's thighs for extra leverage as energetically penetrated her, pushing ever deeper into Sam's welcoming pussy until the thick head bumped against her cervix.

"Oh fuck! Seven!" Sam gasped as Phoebe's hips rocked, driving the synthetic shaft deep and hard into her welcoming wetness.

"Seven already? Good," the doctor said, rewarding her by sliding a hand up over her bare stomach and cupping one of her gently swaying breasts with a warm hand, squeezing the yielding flesh into a tight cone.

"Yes, yes," Sam sighed as the woman fondled her naked breasts, her slim hips continuing to relentlessly pound her pussy.

"My, don't you have lovely boobs, and such lovely plump little nipples too," Phoebe purred. Her fingers were still oily from the lube, and Sam moaned happily as Phoebe squeezed and tweaked her teats, coaxing them into hard little peaks standing proud of her milky boobs, as plump and red as tiny raspberries. "Now, how does this prototype feel? As good as your own dildo?"

"Mmm, yes, yes! It feels so good!" she panted hotly as Phoebe flicked her engorged nipples with her fingertips sending little electric surges straight to her clit.

"Ooh yes, you're loving it, aren't you?" Phoebe chuckled, her professionalism slipping a little as she slid her hand down over Sam's feverish body to where the thick strap-on plunged in and out, drawing her slick thumb across the throbbing pearl of her clit. "Tell me how much you like it."

"Yes, yes, please, I love it! Don't stop!" Sam panted feverishly, her body jerking, her breasts swaying in time with Phoebe's hips. There was something about being helpless and unable to stop Phoebe's thrusting cock that made it especially arousing.

"Good girl, you're loving my lovely hard cock, aren't you?" Phoebe asked breathlessly. She was fucking Sam with long, hard strokes now, seemingly forgetting about recording test results and gathering data, and solely focussed on pleasuring her victim, fucking her harder and faster now, her glasses sliding down over her nose, her breathing laboured, corkscrew curls of dark hair escaping her tight bun and swaying in time with her thrusting hips.

"Yes, yes!" Sam agreed, her breathing reduced to a series of hot, dry gaps as Phoebe increased her pace, teasing Sam's greedy clit as the artificial cock drove deep into her clasping depths and made embarrassingly loud, wet noises with each powerful thrust.

"Are you going to come soon?" Phoebe panted as their slick bodies slapped together, her hips slapping against the backs of Sam's thighs noisily.

"Yes, yes!" Sam squealed, feeling the pressure build.

"Come for me then!" Phoebe ordered, pounding her harder and harder until Sam could take no more.

"Yes, oh God, yes!" Sam squealed as she climaxed, her hot body writhing and jerking against the unyielding straps as she was consumed by the warm blissful flames of pleasure.

As she lay there breathless and completely spent, Sam was aware of Abby's increasingly desperate cries of pleasure. Twisting to her left, she watched through half-open eyes as Jana energetically fucked her friend harder and harder, her hands clutching her fleshy thighs, her slim hips rocking back and forth till Abby came with a long, grateful cry of pure bliss.

Sam lay quietly, her eyes shut, her mind processing what had just happened as her heartbeat slowly returned to normal and the perspiration cooled her hot skin. After a few minutes, she became aware of Phoebe's cool hands unfastening the straps around her wrists.

"So thanks for participating in our little experiment, Sam," Phoebe said, as she moved down to Sam's ankles. "I'm sure our sponsors will be awfully pleased to hear how enjoyable you found their new toys."

"No problem. It really was my pleasure," Sam said in a hoase whisper, rubbing the faint red marks on her wrists then running her fingers through her russet hair, sweeping it back off her moist forehead.

"I don't suppose you're free next week. We have a little more testing to do, and it's rare to find someone who so enjoys the testing process," Phoebe said, a mischievous half-smile playing around her ruby lips.

"Well, I suppose I could make it." Sam said, after the briefest of pauses. "I mean, as long as it's in the name of scientific research.."