Experimental Knot Volume II

Dr. Elena Voss has gone full mad scientist. She now actively drugs her Doberman Rex for longer knots, massive creampie, sloppy oral, and filthy rewards.

Experimental Knot – Part 4: Controlled Doses

Two months had passed since the night Rex accidentally swallowed the prototype vasodilator.

Dr. Elena Voss no longer pretended this was an accident.

The 30 year old vascular biochemist stood in her home laboratory at 11:47 p.m., wearing nothing but an open white lab coat that barely covered her full breasts and left her shaved pussy completely exposed. Her long blonde hair was tied in a loose ponytail that swayed as she moved. The workbench was covered with neatly labeled blister packs and small amber bottles. Her private collection of custom formulations.

She had been busy.

Pill A: Enhanced vasodilator. Longer duration, moderate knot inflation.
Pill B: Potency plus seminal volume booster. Thicker, heavier loads.
Pill C: Combined hyper relaxant. Slower swelling but extreme endurance.
Pill D: Her latest. Knotlock 9. Aggressive blood flow plus delayed deflation. She was particularly proud of D.

Elena picked up two capsules. One B and one D. She crushed them into a small dish of wet dog food, the sharp chemical scent mixing with the meaty aroma. She watched Rex, her sleek black Doberman, eagerly devour the mixture from his bowl, his powerful tongue lapping noisily. Her pulse quickened with clinical anticipation and something far less professional. Heat was already pooling between her thighs.

"Good boy," she murmured, stroking his sleek head as he licked the bowl clean. "Tonight we will test the oral protocol first."

She led him into the living room and sank down onto the wide leather couch, spreading her long legs wide. Her slick pink folds glistened under the soft lamp light. Rex needed no further invitation. The moment she patted her thigh he jumped up, front paws on the cushions, his muscular body looming over her, warm fur brushing her sensitive skin.

Elena leaned forward, green eyes gleaming with hunger. She started slow. Exactly the way she liked it now.

Her fingers gently coaxed his sheath, stroking the emerging red tip until the full length slid out, hot and slick, veins pulsing visibly. She wrapped her soft lips around the tapered head, sucking softly at first, then deeper, letting her tongue swirl around the sensitive shaft. The salty, musky taste flooded her mouth and made her thighs clench with raw anticipation. She moaned around his cock, the vibration traveling straight down his throbbing length.

Rex panted heavily above her, hot breath washing over her blonde hair, hips twitching as she worked him with practiced skill. Elena took him further into her warm, wet mouth, cheeks hollowing, one hand massaging the slowly swelling knot at the base while the other stroked his firm belly. Drool began to drip down her chin as she bobbed her head, sucking noisily, savoring every inch of his growing dog cock.

She spent long minutes like this. Sucking, licking, occasionally pulling off to kiss and lap at the growing knot with wet, sloppy strokes of her tongue, whispering filthy observations between breaths.

"Already responding faster. Pill B is definitely increasing pre ejaculate volume. Mmm, look at you leaking for mommy already."

When his knot had grown to a solid fist size, shiny and swollen, and his shaft was throbbing angrily with need, Elena finally pulled back. Thick strings of saliva connected her swollen lips to his glistening red cock.

"Enough foreplay," she said, voice husky and dripping with lust. "Time for the main test."

She turned around on the couch, climbed on top of him in cowgirl position, and slowly sank down, guiding the thick, chemically enhanced cock into her dripping, eager pussy. The stretch was immediate and perfect, her slick walls parting around his hot girth with a wet squelch. She rode him with deliberate, rolling hips, feeling every vein and ridge drag along her inner walls. Leaning forward, she captured his long, slobbery tongue in her mouth again.

The tongue sucking had become her favorite part.

Elena sucked greedily on Rex’s warm, wet tongue while she bounced, blonde hair swaying wildly, her full breasts pressing and jiggling against his furry chest. The pills were working beautifully. The knot swelled faster than ever. Thick, hot, and unyielding. Locking deep inside her with a loud, wet pop that made her gasp sharply into his mouth.

"Fuck yes, Rex. Look at that fat knot stretching mommy open so wide. You are such a good boy for me. Keep swelling, baby. Stretch mommy’s tight cunt until I can't think."

She ground down harder, voice growing breathier and dirtier with every bounce, her words spilling out between messy tongue kisses.

"Come on, big boy. Swell up bigger for mommy. I want to feel you lock me so tight I cannot even move. That is it. Good dog. Fill mommy’s greedy pussy with that huge throbbing knot. You love breeding your owner, don't you? Pumping all that hot cum deep inside me while I ride you like a desperate slut."

Elena’s dirty talk flowed naturally now, low and filthy, right against his muzzle as she sucked harder on his drooling tongue between sentences, saliva running down her chin and onto her bouncing tits.

"Yes, just like that. Pound mommy from below. Make me your bitch. I can feel you getting even bigger inside me. Fuck, it is so deep. You are going to make mommy cum all over your big dog cock."

The tie lasted longer this time. The combination of pills kept the knot inflated for nearly an hour and a half. Elena came three times during the extended ride. Once from the initial lock, her walls clamping down hard around the massive bulge. Once from the relentless internal pressure grinding against her g spot. And once from the slow, grinding overstimulation while tied, her body shaking uncontrollably.

When Rex finally erupted, the load was massive. Thick, heavy ropes of hot dog cum blasted against her cervix in powerful jets, filling her so completely that her lower belly visibly swelled outward. Creamy white overflow squirted out around the massive knot in messy, rhythmic pulses, soaking the couch beneath them and running down her thighs in sticky rivers.

Elena stayed impaled, trembling violently, still lazily sucking on Rex’s tongue even as the aftershocks rolled through her. Her scientific brain tried to take notes, but the words kept dissolving into soft, broken whimpers of pure pleasure.

After another twenty minutes, when the knot had only slightly deflated, she whispered against his muzzle, voice hoarse and satisfied.

"Tomorrow we try triple dose of D with a new oral enhancer. For science."

Rex gave a contented huff, his knot giving one final possessive throb inside her.

Elena smiled faintly, already thinking about the next formulation, her body still buzzing with the afterglow of being so thoroughly used.

Experimental Knot – Part 5: Oral Protocol

The next evening arrived faster than Elena expected.

Dr. Elena Voss stood once again in her dimly lit living room, completely naked this time, her white lab coat tossed carelessly over the arm of the couch. Her long blonde hair hung loose around her shoulders, a few strands already sticking to her flushed skin. On the coffee table sat three crushed capsules of Knotlock 9 and a small blue pill she had finished developing that afternoon. Oral Enhancer Alpha. It was designed to dramatically increase saliva production, heighten sensitivity in the canine tongue and shaft, and amplify the dog’s urge to thrust without triggering full knot inflation.

She wanted control tonight. She wanted to focus purely on the oral side.

Rex watched her with eager, dark eyes as she mixed the pills into his favorite wet food. The moment the bowl hit the floor he attacked it, powerful jaws crunching and lapping until every trace was gone. Elena’s heart raced as she knelt on the soft rug in front of the couch, her full breasts swaying gently with the movement.

"Come here, baby," she purred, patting her thighs. "Mommy has a special treat for you tonight."

Rex padded over immediately, his sleek black body towering above her as he stood. Elena reached up and gently coaxed his sheath with both hands, stroking slowly and firmly. The red tip emerged quickly, already glistening. She leaned in, warm breath washing over the sensitive flesh.

"That is it, good boy. Get nice and hard for mommy."

She started with soft, teasing kisses along the tapered head, then opened her mouth and took him in. Her lips stretched around the hot, smooth shaft as she sucked gently at first, tongue swirling in slow circles. The taste was strong and musky, sending a fresh wave of heat straight to her core. She moaned deeply around him, the vibration making Rex’s hips jerk forward.

"Mmm… you taste so fucking good tonight," she whispered, pulling off just enough to speak before diving back down. "Mommy loves sucking her big dog cock. Look at you twitching already."

Elena worked him with practiced hunger. She bobbed her head steadily, taking more of his length into her warm, wet mouth with each pass. Drool poured freely from the corners of her lips, dripping down her chin and onto her heaving breasts. She used one hand to stroke the base of his shaft while the other gently massaged his heavy balls, feeling them tighten under her touch.

Rex panted loudly above her, hot breath ruffling her blonde hair. His hips began to thrust in short, instinctive pumps, fucking her mouth with growing urgency. Elena welcomed it, relaxing her throat and letting him slide deeper until the tip bumped the back of her mouth. She gagged softly but kept going, eyes watering with pleasure as thick strings of saliva stretched from her lips every time she pulled back.

"Fuck yes, Rex. Use mommy’s mouth. Thrust into my throat like the horny dog you are," she gasped between sloppy strokes, her voice thick and filthy. "You love face fucking your owner, don’t you? Getting all that warm drool all over your cock while I suck you dry."

She sucked harder, cheeks hollowing, tongue pressing flat against the underside of his shaft. The Oral Enhancer was clearly working. Rex’s cock seemed even more sensitive, twitching and leaking pre cum steadily onto her tongue. She swallowed every drop greedily, moaning louder.

"Give mommy more. Leak for me, baby. I want to taste how much you need this."

For nearly twenty minutes she worshipped him. Long, wet, noisy sucks. Deep throating as far as she could without triggering the knot. Sloppy kisses and long licks along the entire length, paying special attention to the swelling base without ever letting it push past her lips. Her own arousal dripped down her thighs onto the rug as she lost herself in the act, one hand slipping between her legs to rub her swollen clit in time with her sucking.

When Rex’s thrusting grew frantic and his balls drew up tight, Elena knew he was close. She pulled back just enough to look up at him with lust filled green eyes, lips shiny and swollen.

"Cum for mommy, Rex. Shoot it all in my mouth. Fill your dirty little bitch with that hot dog cum. Don’t hold back."

She dove back down, sucking with desperate intensity, tongue working furiously. Rex’s entire body tensed. With a deep, guttural growl he erupted.

Thick, powerful jets of cum blasted across her tongue and straight down her throat. The load was heavy and voluminous thanks to the pills, rope after rope flooding her mouth faster than she could swallow. Creamy white seed spilled from the corners of her lips, running down her chin and dripping onto her breasts in sticky strands. Elena moaned loudly around his pulsing cock, swallowing as much as she could while the overflow made a complete mess of her face and chest.

She kept sucking gently through his orgasm, milking every last drop until his spasms finally slowed. Only then did she pull off with a wet pop, strings of cum and saliva connecting her lips to his still twitching shaft.

Elena sat back on her heels, breathing hard, her face and tits glistening with his cum. She licked her lips slowly, savoring the thick, salty taste, then looked up at Rex with a satisfied, wicked smile.

"Good boy. Such a good fucking boy."

She wiped a thick strand of cum from her cheek and sucked it off her finger, eyes half lidded with pleasure.

"Tomorrow we combine the oral enhancer with a low dose of Knotlock 9 again. But tonight… mommy needs to ride that afterglow for a while."

Rex panted happily, tail wagging slowly as he leaned down to lick her cum covered face.

Elena laughed softly, already planning the next experiment in her head.

Experimental Knot – Part 6: Full Breeding

One days later, Dr. Elena Voss could no longer wait.

She had spent the morning finalizing the ultimate combination: a moderate dose of Knotlock 9 mixed with the new Oral Enhancer Alpha and a fresh seminal volume booster. The pills were already crushed and waiting in Rex’s bowl. The moment he finished eating, she felt the familiar rush of heat between her legs.

Elena dropped to her hands and knees on the living room rug, completely naked, her full breasts hanging heavily and her ass raised high. Her long blonde hair spilled across the floor like a golden curtain. She looked back over her shoulder, green eyes dark with lust.

"Come here, Rex. Mommy needs you to fuck her properly tonight."

Rex padded over, his sleek black body already showing signs of the pills working. His red cock was sliding out, thick and ready. Elena reached back and guided the tapered tip to her dripping entrance.

"Put it in me, baby. Mount your dirty bitch."

The big Doberman did not need telling twice. He reared up, front paws landing heavily on her back as he thrust forward. His hot, slick cock speared into her soaked pussy in one powerful stroke, stretching her walls wide open with a wet squelch. Elena cried out in pleasure, fingers digging into the rug.

"Fuck yes! That is it, Rex. Shove that big dog cock deep inside mommy. Breed me like the horny slut I am."

Rex began pounding her hard in doggystyle, his hips slamming against her ass with loud, rhythmic slaps. Each thrust drove him deeper, the chemically enhanced shaft dragging along her g spot with every stroke. Elena pushed back to meet him, her voice turning into a steady stream of filthy encouragement.

"Harder, baby. Pound mommy’s tight cunt. You love fucking your owner from behind, don’t you? Making me your personal breeding bitch. Yes, just like that. Deeper. Stretch me open."

Her full breasts swung wildly beneath her as Rex rutted faster. The knot at the base of his cock was already starting to swell, bumping insistently against her stretched lips with every powerful thrust.

"Feel that fat knot growing for me? It is going to lock inside and fill me up so good. Keep going, good boy. Make mommy cum all over your cock."

Elena came hard within minutes, her walls clamping down around him as she screamed into the rug. Rex did not slow down. He kept hammering into her, growling low in his throat, his heavy balls slapping against her clit.

After several long minutes of relentless doggystyle fucking, Elena’s arms gave out. She collapsed forward onto her chest, ass still raised high for him.

"Turn me over, baby. Mommy wants to look at you while you breed me."

Rex pulled out with a wet pop. Elena quickly rolled onto her back and spread her legs wide, pulling her knees toward her shoulders. Rex mounted her again in full missionary position, his front paws on either side of her head. His thick cock sank back into her dripping pussy with ease.

"Yes… fuck me face to face, Rex. Look at mommy while you fill her up."

The angle was even deeper now. Elena stared up at him, eyes glassy with pleasure, as he thrust into her with long, powerful strokes. Her hands roamed over his furry chest and sides, pulling him closer.

"You are so deep inside me, baby. Hitting mommy’s womb with every thrust. Such a good breeding dog. Pump all that hot cum into your owner. Make my belly swell with your load."

Rex’s knot swelled rapidly, stretching her wider and wider until it finally popped inside with a loud, obscene squelch. The massive bulb locked behind her pubic bone, grinding relentlessly against her g spot. Elena’s back arched off the floor as another powerful orgasm ripped through her.

"Fuck, it is so big! You are locking mommy so tight. Don’t stop. Keep thrusting while you are stuck inside me. Fill me up, Rex. Breed your filthy little bitch."

The tie lasted over an hour. Rex kept making small, instinctive thrusts even while locked, the huge knot pulsing and throbbing deep inside her. Elena came twice more, her body shaking uncontrollably, dirty talk spilling from her lips the entire time.

When Rex finally reached his peak, the load was enormous. Thick, heavy ropes of hot dog cum blasted directly against her cervix in powerful jets. Her lower belly visibly swelled as he flooded her, the pressure so intense that creamy white seed forced its way out around the massive knot in messy, gushing spurts, soaking the rug beneath them.

Elena trembled beneath him, whispering hoarsely, "Good boy… fill mommy so full… such a perfect breeding dog."

After the knot finally began to soften and Rex pulled free with a wet flood of cum pouring from her stretched pussy, Elena was not done.

She pushed him gently onto his back on the rug and crawled between his hind legs. Her green eyes were glazed with pure depraved lust as she spread his cheeks with both hands.

"Now for mommy’s favorite reward," she purred.

Elena leaned in and pressed her tongue flat against Rex’s tight, musky asshole. She licked slowly at first, savoring the filthy, animal taste, then grew bolder. Her tongue circled the puckered hole, probing gently, pushing inside as far as she could. She moaned loudly into his ass, the vibration traveling through him as she ate him out with hungry, sloppy strokes.

"You taste so fucking dirty, baby. Mommy loves rimming her good boy’s ass after he breeds her. Such a nasty little treat."

She licked and sucked with depraved enthusiasm, tongue fucking his hole while one hand lazily stroked his softening cock. Thick globs of their mixed cum still dripped from her own pussy onto the rug as she worshipped him.

Rex panted happily, tail thumping weakly against the floor while Elena continued her lovely, filthy rimjob, completely lost in the depraved aftercare.

She finally pulled back, lips shiny and swollen, and smiled up at him with a wicked, satisfied grin.

"Next time we go even higher on the dose. For science… and for mommy’s greedy holes."