She couldn't sleep. Her insides were tied up in knots and her hindquarters were burning up. And she just couldn't get that mare out of her head!

Tenderheart suppressed a sigh. The Hearts had rolled out their portable cots in the main hall of the Golden Oaks Library and were already sleeping even though it was still early. A self proclaimed night owl, the light blue pony just couldn't get comfortable, but didn't want to disturb her two older sisters by tossing and turning. She slowly lifted her head and glanced about. She could see their slumbering, featureless shapes under hospital sheets and blankets. The whineysome MacHoovey had stopped by with the three portable cots after hearing that all three sisters were going to camp out in the library, but Redheart didn't even blink an eye at the nicely muscled stallion. Red had promptly suggested they turn in and not have a nightlong gabfest as they did at home; they were on the job.

But the whole thing was just weird!

When Tenderheart had seen their patient lying unconscious in bed, she couldn't explain the sudden interest she'd felt. She'd allowed herself to get closer and closer... and then that was when the mare's scent hit her. Her ears had perked up, twitching. She didn't think there was a smell quite as delicious as Twilight Sparkle's. The more she looked, the more she wanted to touch, and when she'd leaned right over, she'd felt an enormous urge to stroke the sleek and well groomed coat, accompanied a sudden, unfamiliar feeling that resulted in a gush of moisture from her marehood. From the time her sisters had caught her that close to the patient, she hadn't been able to stem the ache between her legs. She'd tried crossing her legs through dinner or thinking about medical procedures afterwards, but the former simply increased the throbbing and the latter always ended up... dirty... somehow. She couldn't even recall when a pony, anypony had this sort of effect on her. Especially a mare!

She couldn't stand it.

With a heady mixture of fear, guilt and arousal, Tenderheart inched a hoof down her sleek barrel and past the taut belly she kept toned with regular exercise. Her soft folds were already drenched with arousal. She folded her her pillow, pressing it to her muzzle with one hoof as she teased into her delicate, slippery moistness with her hoof. A jolt of pleasure shot through her and she bit down hard on the pillow in an effort to stay quiet.

She imagined Twilight Sparkle leaning over her with a half-lidded, sultry gaze before and giving her a wet, sloppy kiss. The unicorn would press down, purple stroking rythmically on light blue, rubbing their cheeks together and twining their necks. The mare's tongue would be long and agile. Purple hooves would slide tantalizingly down her heaving flanks, easing her legs apart before... she whimpered involuntarily and froze.

All she heard was the gentle breathing of her sisters and her own quiet, laboured breathing. She really couldn't take it anymore!

Dampness trickled down her leg as she rose silently, pushing aside her blankets with infinite care. She slowly, on hooftips, climbed the stairs, breathing through her mouth in an effort to stay as silent as possible. Tenderheart knew what she was about to do was morally and ethically wrong, and maybe sick and twisted, but her heart was racing and her mind was an erotically charged jumble. She reached the top and eased the door open.

Moonlight shone down from Twilight's loft. She shut the door behind her and quickly cantered up the stairs in a heady rush. Tenderheart's stomach trembled with anticipation and excitement and as she approached the bed. Twilight was still sleeping in the same position as the sisters had left her. She'd been turned and was away window, her blue and pink streaked hair fanned adorable under her. She stopped before of the mare. The little unicorn's scent was just simply incredible, she panted to herself. She drew in a slow, deep breath, enjoying the fragrance that set her marehood tingling.

So cute, Tenderheart thought, reaching between her legs. She pushed her swollen lips apart and groaned as she began to run her hoof up and down her mound. She could feel the fresh gush of moisture and her legs felt weak. She put one hoof on the headboard as she pleasured herself with a ferocity that was shocking, her hoof blurring over her slopping folds. She groaned and squeaked softly. Sweat began to lather her coat, and beaded on her muzzle. The earth pony licked her lips as she stared at Twilight Sparkle's adorable face. The unicorn's scent was overpowering all coherent thought, the building delight wiping away any thought of wrong doing.

She whimpered, biting her lower lip, and rubbed harder. She could feel the tingling sensations building, building, wrapping tighter, and tighter, oh Celestia, she was so close now, she was almost there...

"What are you doing?" whispered a soft voice in her ear.

She froze with a squeak, her muscles locking painfully, afraid to even move as a warm body pressed close.

"Oh my," the pony behind her said, as a hoof guided her own away from her painfully throbbing loins. "I see." She felt the presence recede and turned her head slowly.

Redheart stood hard against her, holding the younger Heart's hoof in her own. Tenderheart didn't want to look her in the eye, so ashamed she was at being caught clopping at the bedside of a patient.

"Sis, I-I-" she swallowed, suddenly aware at a sudden gush of pleasure between her legs. Her eyes widened in abject horror. She felt so ashamed that she might be aroused at being caught, afraid of what it meant to the spiraling arousal. She knew, one touch, and her pleasure would pour out in a heavenly libation of erotic rapture.

Redheart's her face was serenely calm, but her eyes burned with a fire that intensifiedTenderheart's guttering desire.

"It's okay," the voice reassured her. "I understand."

"Sis?" she whispered, caught between desire and shock, unable to think, incapable of processing what was happening. All she could do was scream inside just one more, just one more, and she would spray her desire all over the adorably slumbering mare's face. The thought caused the smoldering to flare into a blaze of lust. She squeaked as Redheart pressed down hard on her back. She could feel the moisture of her sister's arousal on her flank as the light grey mare ground her hips against her. She groaned and her eyes, half-lidded with desire, fluttered as her own sister's teeth nibbled along the edge of her ear.

"Can't you hear her calling us? Listen." Tenderheart forced her eyes open against the awful, abominable pleasure her sister was teasing her with and stared at Twilight's silent face. Each of Red's gasps, each moan shivered through her. An erotic haze had settled on her, enshrouding her. And then she heard it. It was faint, but definitely, undeniably irresistible. She gave a long, shuddering, lingering sigh.

"Yesssss," Redheart hissed into her ear, as she thrust against her sister's flank, causing a tremor to run down the cornflower pony's spine. Red's weight was pressing down harder now and Tenderheart put both her forehooves on the headboard to keep from collapsing, her sister's panting filling her ear. The younger mare felt the moisture of Redheart's arousal making a slick spot on her dock. Big sis is bucking me, big sis is bucking me, she chanted in commingled dismay and desire.

"She's just so," Redheart whimpered into her ear as she ground her marehood into her sister's rump and ended with a sigh, "so, delectably adorable, isn't she?" Her tongue ran along the ridge of the younger mare's ear, which she ended with a nip. Tenderheart responded with a barely muffled squeal. She could see her own desire dripping down her bluish quarters, past her hoof and onto the floor.

"When I saw her, lying on the archive floor, I wondered how I'd never seen how beautiful she was. And when I picked her up-" the light grey mare paused with a groan and a particularly hard snap of her loins against Tenderheart who responded with a near feral growl. The younger sister's lust was stoked to such an incendiary aura, where the tinder of the shock, shame and disgust burst into an incandescent, raging lust blind to familial ties. Her mind was so sensually muddled that she just didn't care who was teasing her to an overpowering craving.

Redheart continued, her voice quavering with wanton desire, "it was like an electric shock. I couldn't think straight!" She giggled at her choice of words, then gave a soft cry as she thrust against her sister once again. "I couldn't get her out of my mind; it was like being in heat all over again, but just for her, only for her." Tenderheart could feel her sister's lips against the back of her neck as the lust crazed mare began to rub herself furiously against her dock, Red's juices seeping down past her sister's tail, mingling with her own arousal that dripped from quivering folds. The smaller mare's body jolted with each thrust upon her backside.

She was drowning in pleasure, her mind a shivering, lathered mass that pleaded for release. Her staid, gentle, eldest sister was rubbing her sopping core against her dock with wanton abandon, breath ragged with her desire. She had never seen the pink maned mare in such a frenzy, even when she sequestered herself during her first heat. Her sister was so charged with sexual energy that it propelled her to even greater heights of arousal.

"Let's show our little librarian how much we want her, need her, shall we?" Redheart's voice rose to a feverish squeak as she furiously thrust against Tenderheart's delicate behind, her hooves gripping the smaller pony's flanks, the blue mare's tail raised over her croup in fully aroused display. The younger mare's heart thundered, rapture coursing through her, her long eyelashes fluttering from the pent up pleasure raging inside. Her head was hanging down, face was so close... so close to the unicorn's own... she bit the pillow with her teeth, a final act of will, her eyes locked on Twilight's long, thick horn.

"Oh, Celestia," Redheart's frantic squeal was almost too much to bear. The younger mare was mindless with passion, her tongue lolling out of her vacantly grinning mouth. "I'm close... I'm close... almost..." Redheart suddenly flicked her tail downward, the silken strands snapping against her sister's core.

Pleasure exploded from her loins. Tenderhart's eyes rolled up as she screamed into the pillow caught tight between her teeth, her haunch jumping and quivering uncontrollably. The pleasure spiked again and again as Redheart's tail continued to whip at her marehood with each convulsive thrust, the white pony arching with each ferocious snap. The younger Heart's rump was drenched by the pink maned mare's release, her own desire spraying from her blue and pink folds onto the wood floor again and again as her frenzy peaked again and again, higher and higher. Her sister's teeth bit hard at her shoulder, the pain goading her, the sounds of Redheart's groans and growls as the older mare's coat shivered against hers, each pulsing orgasm pushing her own to greater and greater bouts of ecstasy.

Tenderheart felt something warm and wet on her cheek. She didn't know anything, anything at all but for the glowing feeling that was moving sluggishly through her, small shocks of pleasure, her mind was completely blank.

"Tend," came Red's hoarse whisper. Tend? What was that? Tend... was it a.... she couldn't understand what was being said in her ear. Oh, wait, that was her name... right? Her sisters' nickname for her. Okay. So I'm Tend...

"Open you eyes, little sis," the voice said. "I've got something to show you."

Tenderheart's eyelids finally fluttered open. She had collapsed, sprawled, her body hanging off the edge of Twilight Sparkle's bed, her sweat mane stringer and slick with sweat. Her coat was still shivering from aftershocks of pleasure, her thighs felt as if she'd been dipped in oil. Redheart was making long sensual licks of her cheek and her eye had a wicked hungry gleam.

"Ever seen the siphon procedure?" she grinned. The devilish grin on her sister's normally innocent face was just as arousing and she felt an answering tingle. She couldn't help catching her breath as she realized what Redheart was suggesting.

"No," Tenderheart croaked in reply. She coughed, clearing her throat, trying to ignore the lassitude or the aftershocks of pleasure that ran the length of her limbs. She turned to see the unicorn's head so close to her own, the magnificent alicorn protruding from the little mare's head. She had to stifle a whimper as desire began to flow back into her. Her limbs felt so heavy, left rear hoof still twitching slightly.

"Watch and learn, sister dear," she said, still standing over the collapsed mare. She leaned forward and deliberately ran her lips lightly over Twilight's horn.

"Red, are you sure-" Tenderheart began, before the last vestiges of will fled before the desire that was building within her once again.

"Oh," Redheart replied, nibbling gently along the underside of the spiraling shaft. "I'm sure she'll think of some way to thank us. Now," she said in a mock-severe tone, "observe."

Redheart ran her tongue up one side and down the other, pausing at the tip every so often to swirl her tongue around the tip. The Younger mare was amazed; who would have thought her sister would know so much about alicorn siphoning, and in such a practical way? Twilight shifted and moaned.

"Oh, buck!" Tenderheart exclaimed, concerned. "Is she awake?" she wondered, half in trepidation, half in anticipation.

"No," Redheart murmured around the horn. "Sometimes they react during the siphon," she paused to swirl her tongue at the tip once more, "but most don't wake until enough magic has been siphoned out." She grinned as she nipped the base of the alicorn. "And Twilight is very powerful." Tenderheart smiled at the thought.

Redheart then took the horn in her mouth and inched down, swirling her tongue around the stiff ridges as she took more and more into her mouth. The young nurse watched with glazed, wide eyes, her breath getting shorter. She could feel the moisture seeping from her marehood's folds as desire filled her. Redheart then raised her head, letting the alicorn slide out until she held only the tip in her mouth, all the while running her tongue around and around. Tenderheart stumbled to her hooves to get a better look, thinking how shockingly erotic a medical procedure seemed.

Sweat beaded on Twilight's forehead and she groaned again. The eldest Heart began to bob her head, the thick shaft sliding easily between her wet lips. In moments, Tenderheart could see a faint glow to the saliva that was sliding down onto the mare's forehead as her sister continued to suck ardently on the horn. There was an intense expression on the unicorn's face and when Redheart took the alicorn from her mouth, the expression eased. The tip glowed, trickles of the thick, glowing magical substance was dripping from the tip and . The earth pony tossed her head with a soft nicker, licked her lips and smiled.

"Oh, she's so tasty!" The older nurse giggled, then glanced slyly at Tenderheart. "Wanna try?" The look on the young mare's face was all the answer she needed to give, as she approached tentatively.

"I... I've never..." She blushed at her halting admission.

"Siphoned before?" Tenderheart shook her head. "Lips and tongue," the head nurse instructed. "No teeth until you know how much pressure you can use; horns can be a bit temperamental and may chip if you bite down too hard. Take the tip in your mouth."

The blue mare obeyed, sliding Twilight's long shaft into her mouth. She marveled at the feel of it, smooth and ridged. She swirled her tongue around it as she'd seen her sister do and felt a small spurt of something gooey erupt onto her tongue. She snorted with arousal, pleasure bursting on her palate as the magic dissipated, teasing her nerves, followed by a sudden gush from her core. Her eyes fluttered closed. She just had to have more!

"Try to relax your jaw and breathe through your nose," Redheart said as if reading her mind. "Don't take too much; you're inexperienced and..." Redhearts mouth gaped as Tenderheart enthusiastically put both forehooves on the bed and thrust herself down the shaft until her lips touched the base, her eyes screwed tight with pleasure. The young mare bobbed her head up and down the unicorn's rigid horn in a frenzy, sucking as hard as she dared. The pained expression returned to Twilight's face and the unicorn moaned loudly. The young earth pony frantically swallowing the pre-alicorn, her throat working as soon as the tip spurted, her coat shivering with delight. She could feel her folds winking as it throbbed, dripping from the intensity of having an almost pure form of magic dribbling across her tongue. Twilight's scent mixed with the sharp odor of alicorn and the mares' arousal was a heady, intoxicating blend. Her inner muscles clenched rhythmically along with her siphoning.

Unable to stop herself, Redheart thrust her muzzle hard against Tenderheart's marehood, her long tongue thrusting into its slick, wet, grasping depths. The blue earth pony whinnied loadly as she felt the long thick tongue invading her and she pushed her haunches back, welcoming the thick organ. Both nurses groaned with desperate passion, each working with increasingly frantic movements. Tenderheart breathed heavily through her nose with small mewling sounds when her sister's skilled tongue unleashed more mare moisture from her core. Her groans became more and more guttural until Redheart suddenly pulled back, put her tongue against the small protruding nodule at the head of Tenderheart's marehead and fluttered.

Tenderheart froze at the sensation of having her most private place so effectively and efficiently stimulated and with a querulous cry, her pleasure washed over her, her flanks bucking and twisting even as she continued to suck on the long alicorn.

Twilight Sparkle was moaning continuously now, right alongside the impassioned earth ponies and Redheart saw the telltale shivers along the unconscious unicorn's coat.

"Quick, Tend, off!" The younger nurse slide the alicorn out of her mouth and Redheart wrapped both her hooves around the long shaft and began to pump quickly.

Sweetheart had been awoken by the commotion upstairs and had jumped up to investigate, thinking the unicorn mare had woken up on her own. Spontaneous recovery was very common, although in Twilight Sparkle's case, unlikely due to the strength of the spell. When she had opened the door, she had immediately noticed the smell of discharged alicorn and the strangely arousing sounds of from the loft. But when her eyes had been drawn to the bed, she had frozen in shock at what she was seeing. Her eldest sister, a mare of impeccable poise and taste, her hooves wrapped firmly around the patient's alicorn, pumping it furiously, her other sister, fallen on her haunch, staring with glazed eyes and a goofy smile on her face. Her mind could not even comprehend what was happening but with only one response.

"What the hay?!?!?" she screamed at as Twilight gave a gutteral growl. Alicorn erupted from Twilight's horn in a straight, steady pulse splashing in her mouth, against her face and chest, in her mane. Redheart, heedless with accomplishment and ignorant of her sister's intrusion, continued to pump, the alicorn still spurting from the tip of the unicorn's horn, the small librarian's body quivering as the magically laced goop continued to erupt. The arc, the thickness, the smell of the alicorn was incredible, the amount, impossible.

Tenderheart had turned around at the scream of horror in time to see Sweetheart be practically hosed by the alicorn... all that yummy, nummy alicorn... on her sister's face...

Sweetheart, to her own horror, swayed, her eyes clouding as the pleasure of the magic tingling all over her coat began to overpower her with alicorn driven need. She gasped in surprise as the magic dissipated in her mouth. As the flow of alicorn ebbed, Sweetheart fell heavily to her knees, panting, her eyes dilated from the alicorn.

"Sis.... Tend... what?" was all she managed to get out before being pinned by two pairs of half-lidded, lust crazed mares. In her mind, a small voice screamed about how wrong this would be, but was silenced when she was tackled by Redheart and Tenderheart. Their tongues were everywhere, on her throat, her chest, even her fetlocks and wow did it ever feel good! All coherent thought departed under the oral assault. Her pleasure spiked as Tenderheart kissed her roughly, her sister's tongue probing her lips for access. The blue mare's hooves were everywhere, kneading and stroking. Redheart had wrapped her forelegs tightly around her dock, pulling her roughly against her lapping tongue as it slathered methodically up and down her unfolding marehood. To her shame and pleasure, Sweetheart opened her mouth, accepting, encouraging her younger sister to plunder her tongue with an embarrassingly feverish groan. The mares moaned as their tongues danced. Redheart, not to be outdone, thrust her tongue into Sweetheart's core, licking and plunging furiously, her forehooves pushing her legs even wider. Sweetheart could not believe how quickly she was being driven to orgasm, and by her own sisters-

The thought was left unfinished as the pleasure overwhelmed her.

Sweetheart screamed as her orgasm hit, wrapping her forelegs around her younger sister, hugging her close, her coat trembling. Red's tongue continued its assault, driving her from climax to climax, each more and more intense. The pink pony thought her heart was going to burst. Her arms dropped limply from her sister's shoulders, who was nipping at her pinned ears and she stared down at the pink mane between her hocks. Their sapphire eyes locked and she tried to plead with her expressive orbs for mercy. Redheart's smirking response was a promise that triggered another orgasm by itself. She cried out, hoarse and plaintive, her hind legs kicking and swaying with each peak, her forehooves moving listlessly, unsure of whether she should be grasping the pink maned head between her legs or the blue mare stroking her flanks and rubbing her cutie mark. Her remaining strength left her and she fell back as Redheart relented and looked up at her sister, her muzzle liberally covered with the mare's juices. The white and blue mare wriggled close, sandwiching the gasping nurse, her coat shivering with post-orgasmic aftershocks, her hind legs twitching, her eyes rolling as her mind tried to resurface from the ebbing swell of pleasure.

"Red,... Tend,..." was all the mare could say between gasps. Sweetheart couldn't believe what had just happened. Her own sisters had just driven her to an orgasmic height that she'd never achieved before with anypony. What could have possibly possessed her sisters both accomplished and professional nurses to suddenly assault their patient.... assault her? Her heart was still beating a rapid staccato when Tenderheart wiped something from he ear. Before she could focus or move, the younger mare thrust her hoof into her gasping mouth.

An intense, velvety bliss washed over her, and she felt her core gush a little at the feeling as the gob of alicorn dissipated on her tongue, her eyelash extensions fluttering as she fought to keep them open.

Red exchanged a wicked smile with her light blue sister, then rolled onto her back.

"Sweeeeeeet," she whinnied softly, "I need someone to help me," she trailed a hoof down her stomach to her core, "here." The white streaked lavendar maned pony's eyes followed the hoof hungrily, her mouth open and panting. The white pony's marehood was slick, dripping with sticky, translucent marecum. Sweetheart couldn't look away from the soft, pink, inviting folds...

And she could never say no to her sister.

Author's Note

Wow, first clopfic chapter ever is complete. What did you think? Comments and suggestions welcome!

Twilight Sparkle hasn't even woken up yet, but is already having an effect. Will the next day for the Hearts be awkweird or will they embrace their new found closeness?

Will Twilight Sparkle wake up, having had so much alicorn siphoned from her?

Applejack is planning to visit, what will happen if she runs into the Hearts?

Spike is sending a missive to Canterlot, what will be the response?

And just what was the reagent that Twilight used?

Only fourteen more days to Hearts and Hooves Day! Can Equestria survive the oncoming onslaught? Find out more in the next chapter!