Experimental Knot Part 1

Dr. Elena Voss' experimental vasodilator pills was swallowed by her Doberman.

[Disclaimer: This is entirely fictional erotica created for fantasy purposes. It does not reflect real events, nor does it promote, endorse, or condone bestiality, animal abuse, or any illegal/non-consensual activities in reality. Strictly for consenting adults 18+. If you are offended by taboo themes, please do not read.]

Dr. Elena Voss slammed her apartment door shut after a grueling twelve-hour shift at the pharmaceutical lab. At thirty, the single biochemist had poured her career into developing a new blood pressure medication, a potent vasodilator that relaxed smooth muscles with ruthless efficiency. Her white lab coat, slung over her arm, felt heavier than usual. She tossed it onto the kitchen counter, not noticing the faint rattle from the pocket where a few stray sample pills had tumbled in during a rushed meeting.

Rex, her sleek black Doberman, bounded in from the living room, his muscular frame rippling under short fur. The dog nosed at the counter, tongue lolling as the pills spilled out with a soft clatter. He snatched them up in one gulp, crunching them like his usual treats, tail wagging furiously. Elena barely glanced over, kicking off her heels. "Good boy, Rex. Mommy's home."

She showered quickly, the hot water easing the ache in her athletic legs from hours on her feet. Her body stayed toned from weekend runs and gym sessions, her 32D breasts firm against the steam-fogged glass. Dressed in a loose tank top and yoga pants, she flopped onto the couch with a glass of wine, scrolling her phone. Rex paced nearby, whining softly.

An hour later, a low growl pulled her attention. Rex lay on the floor, hind legs splayed, his sheath swollen and exposed. A thick, red rocket of a cock protruded fully, nine inches long and veined, the tip tapered and glistening with precum. At its base, a bulbous knot throbbed, three inches wide, pulsing with unnatural vigor. The pills. Fuck, the vasodilator had hit him hard, flooding his system with relentless blood flow, trapping that erection in overdrive.

Elena's stomach twisted. The vet? No way. "My dog ate experimental boner pills and now his dick won't go down"? She'd lose custody, face questions, maybe lab audits. Her cheeks burned at the thought. Rex whined again, humping the air, his massive cock slapping against his belly with wet smacks. She couldn't leave him like this. Heart pounding, she coaxed him to her bedroom. "Easy, boy. Mama's gonna fix it."

She guided the hundred-pound Doberman onto her king-sized bed, pushing his shoulders until he rolled onto his back, legs akimbo. His cock jutted straight up, hot and slick, the knot inflating further under her gaze. The musky scent hit her first, sharp and animalistic, mixing with the faint chemical tang of his saliva. Elena knelt between his thighs, her small hand wrapping around the shaft. It burned against her palm, velvet skin over steel hardness, veins throbbing like live wires.

She stroked slowly at first, base to tip, twisting her wrist on the upstroke. Precum oozed from the pointed head, slicking her fingers. Rex panted, hips twitching, but after five minutes, nothing. The drug's endurance boost kept him rigid, unyielding. Her arm ached. "Come on, boy," she muttered, pumping faster. The shaft pulsed, but no release. Sweat beaded on her forehead. This wasn't working.

Desperation clawed at her. She leaned down, breath ghosting the flared tip. The smell intensified, pungent and feral, stirring something dark in her gut. She parted her lips, tongue flicking out to taste the salty bead of precum. Bitter, thick. She hated it, the wrongness of it twisting her insides. But Rex's cock twitched, and a forbidden heat bloomed between her legs. Her pussy clenched, dampening her panties.

Elena took the head into her mouth, lips stretching around the girth. The heat seared her tongue, the flavor overwhelming her senses. She sucked tentatively, cheeks hollowing, then bobbed deeper. Inch by inch, the cock filled her mouth, pressing her tongue flat. She gagged as it hit her throat, saliva drooling down the shaft, but the sensation sparked electricity in her core. Her clit throbbed, nipples hardening against her tank top. She hated how good it felt, the fullness, the dog's helpless whines turning to guttural rumbles.

Her head moved with rhythm now, sucking hard on the upstroke, tongue swirling the underside. She went deeper, forcing past her gag reflex, nose burying in the musky fur at his sheath. The cock shuddered, twitching violently, but held firm. Precum flooded her throat, forcing her to swallow around the invasion. Gagging turned to moans, her free hand slipping into her pants to rub her soaked pussy. Wet folds parted under her fingers, clit swollen and slick. She loved it now, the degradation fueling her arousal, her throat milking that massive dog cock like a vice.

Still, no cum. Rex's endurance mocked her, his knot swelling bigger, balls tight but unrelenting. Elena pulled off with a gasp, strings of spit connecting her lips to the glistening red meat. Her body burned. She needed more. Stripping off her tank and pants, she revealed her athletic frame, toned abs flexing, full 32D tits bouncing free, pink nipples erect. Panties last, her shaved pussy glistened, lips puffy and dripping.

She straddled Rex cowgirl-style, knees sinking into the mattress on either side of his hips. Grabbing his cock, she aligned the pointed tip with her entrance. "That's it, boy. Fuck your mama's pussy." She sank down slowly, cunt stretching around the girth. Inch after burning inch split her open, the veins dragging against her walls. She gasped at the fullness, her juices coating him, dripping down to lube the knot. Bottomed out, she rocked her hips, grinding her clit against his sheath.

Rex bucked instinctively, fast and brutal. She guided him with her hands on his chest fur. "Hump me, Rex. Give it to me hard." He did, pistoning up with jackhammer force, cock slamming her cervix. Her tits jiggled wildly, pussy clenching in waves. Orgasm hit fast, her walls spasming, cream gushing around his shaft. "Fuck, yes! Cumming on your dog dick!" But he kept going, faster, her athletic body glistening with sweat, scent of her arousal thick in the air.

She came again, thighs quivering, nails digging into his fur. Third orgasm ripped through her, vision blurring, pussy squirting onto his belly. Still hard. Breath ragged, she lifted off, pussy gaping and red. "Not done yet, big boy. My ass needs that monster cock." She scooped her own cum as lube, slathering his shaft, then positioned the tip at her tight asshole. "Look at this endurance, Rex. Nine inches of perfect dog cock, knot like a fist. And these tits? Thirty-two D's just for you, bouncing while you wreck my shithole."

She pushed back, sphincter yielding with a pop. Pain flared, then pleasure as he filled her bowels, thicker than anything human. Rex thrust wildly, balls slapping her pussy. She rode reverse cowgirl now, ass cheeks spreading wide, the dirty slide audible over her moans. "Fuck my ass, you stud! Pound it!" Her hand mauled her tits, pinching nipples, dirty words spilling. The friction built, her hole gripping like a glove. Rex growled, hips blurring. Heat bloomed deep, his cock swelling, then erupting. Thick ropes of dog cum blasted into her guts, hot and endless, filling her until it leaked out in creamy rivulets.

Fifteen minutes later, he slipped free, ass prolapsed slightly, cum pouring onto the sheets in heavy globs. But his cock stayed rock-hard, knot throbbing, ready. Elena's eyes glazed with hunger. She wanted it all. Flipping to missionary, legs spread wide, she pulled him over her. "Breed me now, Rex. Knot your mama's pussy."

His tip speared her folds, plunging deep in one thrust. She wrapped legs around his haunches, heels digging in. He fucked like a machine, knot battering her entrance with each slam. Her pussy stretched obscenely, walls rippling, clit grinding his fur. Sweat-slick tits heaved, nipples rasped by his chest hair. "Deeper, boy! Fill me with that cum!" Sensations overwhelmed: the wet squelch of penetration, salty tang on her lips from earlier, his hot breath on her neck.

Ten minutes of relentless pounding, and he came. The knot forced in with a painful pop, sealing her tight. Cum jetted in powerful spurts, bloating her belly, pressure building as her pussy milked every drop. She orgasmed around the lock, convulsing, squirting past the seal. Twenty minutes they stayed tied, his cock pulsing inside her, her fingers circling her clit through aftershocks. Rex panted atop her, finally spent, but Elena lay there, filled and claimed, the forbidden high lingering in every throb.