Lisa's bike tires hissed against wet pavement as she pedaled past the university gates. The late afternoon sun turned her thighs sticky beneath her skirt—three miles uphill always left her breathless and damp in places she'd never admit.

The big Victorian house on Rowan Street stood slightly crooked, its bay window sagging like Mr. Harrison's left shoulder. He'd waved off her first month's rent when she mentioned studying for her phd in mathematics, muttering something about his late wife having loved primes. Her room smelled of lemon polish and mothballs, with a double bed so old the iron frame groaned when she sat.

"Mr. Harrison?" Lisa kicked off her shoes in the hallway. Silence answered. She adjusted the strap of her bookbag—heavy with Markov chain equations.

The kitchen smelled faintly of burnt toast, the teacup by the sink still holding an amber puddle. Upstairs, his bedroom door stood ajar. She caught herself hesitating outside, listening for the shuffle of slippers or the wheeze of his oxygen tank. The grandfather clock in the hall ticked twice before her fingers pushed the door wider. Empty. Bed made military-tight, medication bottles lined up like little soldiers.

Back in her own room, she exhaled through her nose. Cycling uphill had left an ache between her thighs—the kind that throbbed in time with her pulse.

Lisa unbuttoned her blouse, letting it slide down her arms to pool on the hardwood floor. Beneath it, her bra was simple white cotton, ghosting over nipples already tight from the friction of fabric against skin. She rolled her shoulders, felt the dampness clinging to the small of her back where her skirt had trapped heat against her body.

The musky scent hit her when she peeled off her soaked underwear. She held them for a moment, breathing in the sharp tang of herself—her body's quiet rebellion against endless equations and proofs. The gusset was translucent with slick, clinging to her fingers when she let them drop.

Lisa stepped out of her skirt and stood before the full-length mirrored doors wardrobe. Late sunlight slanted through the gap in the curtains, catching juices dripping down thighs. She looked like a watercolor study in desperation—hips sharp enough to graph quadratic equations, ribs rising with each uneven inhale. Between them, her strip or trimmed pubic hair lay dark and damp, framing lips that pulsed visibly when she shifted her weight.

Her breasts barely filled her palms when she cupped them—small and high, the pink nipples puckered tight as unsolved proofs. A mathematician's body, she thought wryly; efficient angles where others had curves, skin stretched taut over wiry muscle. The left one had a freckle just below the aureola, like a decimal point misplaced in an endless calculation. She pinched herself experimentally, gasping when the sensation arrowed straight to her clit.

Numbers flickered behind her eyelids—days marked on mental calendars. Sixteen since her last period, thirty-two days total cycle length. Lisa's lips parted as the realization unfolded: ovulation day. Her body had plotted this trajectory long before her mind caught up. She pressed three fingertips to her slit and came away shining. The viscosity surprised her; not the thin slickness of arousal but something thicker, primal—cellular machinery optimized for conception. A drop pearled on her inner thigh.

The bedside drawer stuck when she yanked it—always did. Beneath a tangle of charging cables and half-dried highlighters, her vibrator lay coiled like a sleeping viper. Purple silicone, modest girth, purchased after reading a journal article linking orgasms to improved problem-solving stamina. She hesitated, fingertips hovering over the ridged surface. Her thesis defense loomed in eleven days, her advisor's emails increasingly terse. The toy felt heavier than its eighty grams when she lifted it.

She didn't lie back so much as collapse onto the quilt, springs singing beneath her. The afternoon's equations still flickered across her vision—eigenvectors pirouetting through Hilbert space—but now accompanied by the scent of her own need. First contact came as a shock; her middle finger skated through folds swollen twice their usual size, the flesh yielding like overripe fruit. Her clit jutted proud and dark beneath its hood, twitching when she circled it counterclockwise. Three revolutions exactly—her brain couldn't stop counting.

Lisa's knees fell wider, heels digging into the mattress. The vibrator lay untouched beside her hip, its presence somehow more obscene than her splayed legs. She crooked a finger inside herself, breath stuttering at the sudden stretch. Her inner walls fluttered around the intrusion, gripping in irregular contractions that mapped perfectly onto Poisson distribution curves. Warmth pooled in her sacrum, syrupy slow, as she imagined filling the hollows of herself with something thicker than digits.

A bead of sweat trickled between her breasts. She'd forgotten to open the window, forgotten everything but the piston-motion of her hand and the slick sounds filling the room. The headboard tapped morse code against the peeling wallpaper. Her moan crested—sharp as a trigonometric function—when she added a second finger and found that spot like solving for x. Outside, blackbirds quarreled in the hydrangeas.

Downstairs, the back door whined on unoiled hinges. Mr. Harrison's knuckles ached around the trowel—he'd been repotting geraniums since lunch. Soil crumbled from his boot soles onto the linoleum. The house felt different; not the quiet of absence but something thicker, humid. A sound dripped through the ceiling like syrup through a sieve. He frowned at the staircase. His knees protested as he climbed, one hand whitening on the banister.

The noise crystallized on the landing—sharp inhalations cut with wet friction. His wife's room had made those same sounds, forty-odd years ago when she'd still bothered. His pulse tripped into an arrhythmia he couldn't blame on the beta blockers. The door stood ajar three inches, enough to catch the afternoon light licking up bare thighs, the arch of a spine lifting off sweat-darkened sheets. Her toes curled like ferns in spring.

Lisa's fingers worked in a blur, her free hand kneading a breast with such force the freckle vanished beneath whitened fingertips. Harrison watched her hips stutter—a faulty piston seeking perfect stroke length. Something in his sternum creaked. He'd seen students come and go for decades, watched their bodies change with seasons, but never like this: calculus made flesh, all derivatives and desperate angles. Her vibrator lay abandoned, its purpose superseded by the raw efficiency of her own hand.

She threw her head back and he saw it—the precise moment variables aligned. Her mouth shaped a silent "oh" as her clit pulsed under frantic circles. Her thighs trembled, toes splaying wide before curling inward like parentheses around some flawless solution. Juice slicked her inner thighs, glistening where it caught the light.

Mr. Harrison's breath fogged the door's varnish. His arthritic fingers dug into the frame, but the ache barely registered. Below his belt, something long dormant stirred with embarrassing vitality. The sensation was absurd—like his prostate had been quietly solving quadratic equations all these years. He should turn away. Should cough. Should do anything but watch this angular girl unravel with the ruthless efficiency of a proof.

Lisa rolled onto her knees with a gasp that smothered itself in the pillow. The fabric muffled her moans but amplified the way her spine arched, vertebrae rising sharp beneath sweat-slick skin. Her ass tilted upward—two pale hemispheres dimpled where her thumbs might grip if anyone were bold enough to claim them. The position stretched her slit obscenely wide, glistening folds parting .

"Fuck—" The pillow swallowed the word but not the tremor in her thighs. Her rhythm faltered, hips jerking in broken calculus aa she added a second finger The stretch burned clean through her, chasing coherence straight out of her prefrontal cortex. Equations dissolved into raw sensation: the scritch of pubic hair against taut inner thighs, the humid puff of her own breath bouncing back from cotton, the—

Cold silicone kissed her clit.

Lisa froze mid-thrust. The pressure was all wrong—alien in its precision, circling the hypersensitive bud with none of her usual jagged desperation. Every nerve ending fired at once, a chain reaction of startled pleasure that snapped her spine straight. Her walls clenched around nothing. Behind her, springs groaned under shifting weight.

Harrison's knuckles ached around the vibrator. His hand shook—not from Parkinson's but from the obscene contrast between purple plastic and her flushed skin. Decades of propriety evaporated at the sight of her hole winking around empty air, glistening strands stretching between trembling thighs. His free hand hovered over the dip of her waist before settling on sharp hipbone. The contact branded him. She felt hotter than fever.

Lisa's gasp hit the headboard and bounced back. The toy traced lazy figure-eights now, alternating between featherlight skims and sudden focused pulses that made her toes scrape the sheets. Her elbows buckled. Drool pooled on the pillowcase. Some distant part of her brain recognized the pattern—Fourier transforms made tactile, sine waves of pleasure building toward some catastrophic limit.

She wrenched her head around. The old man's suspenders cut trenches into his cardigan, his breathing audible over the vibrator's buzz. His thumb shone with her wetness where he'd tested the toy's speed dial. The lenses of his glasses magnified pupils blown wide as event horizons.

Humiliation scorched up her neck. She should scream. Should yank the quilt over herself. Should do anything but lie there slack-jawed while his rheumy eyes tracked the quiver of her inner thighs. Yet when her mouth opened, all that escaped was a reedy "S-sir—" cut off by the vibrator skating lower to nudge her exposed hole.

Harrison watched comprehension flood her face—the exact moment she registered how wantonly she'd positioned herself. How effortlessly he could sheath himself in that glistening heat. His thumb pressed the speed button again, wringing a punched-out sound from her throat as the toy drilled into her clit's underside.

Her fingers twisted in the sheets. Pupils swallowed hazel irises whole. He could graph her conflict in the tension between her thighs—how they jerked to clamp shut only to fall wider when the vibrator switched to pattern three. Precum soaked through his trousers. Twenty years since he'd last touched a woman, and now this taut little equation of a girl was coming apart under his shaky hands.

The vibrator's hum climbed octaves. Lisa's back arched like a drawn bowstring, breasts swaying with each ragged breath. Harrison leaned closer, close enough to count the freckles dusting her shoulder blades, close enough to smell the sweet crisis building between her legs. His free hand settled at the base of her spine, pressing down just hard enough to make her aware of his leverage.

"Please," she whimpered—not a protest but a shattered plea. Her hips stuttered against the toy's relentless circles. The old man's breath hitched as her orgasm hit; her cunt clenched around nothing, juices painting her inner thighs in slick arcs. He kept the vibrator glued to her throbbing clit through every convulsion, drawing out each pulse until her whimpers bordered on sobs.

Lisa's arms gave out. She collapsed face-first into the pillow, her ribcage heaving. The aftershocks felt like live wires under her skin—too much, too bright, her oversensitive flesh flinching at every whisper of air. Mr. Harrison's thumb hovered over the power button. His wedding band gleamed dully in the slanting light.

"Again," he rasped. Not a question. The vibrator's pitch climbed before she could protest. Lisa's back arched off the mattress involuntarily, her body betraying her even as tears pricked her lashes. Her clit was raw—an exposed nerve firing random signals—but her hips kept rocking into the torture. The old man watched her thighs quake with clinical interest, his grip tightening on her hipbone when she tried to squirm away.

A fresh slickness seeped between her legs. She hated herself for it. Hated how her swollen lips clung together with every aborted thrust. Harrison dragged the toy down through her folds, collecting enough wetness to paint glistening streaks across her inner thighs. Lisa bit her lip when he circled her entrance—just once, teasing the rim with the tip before skating back up to her ruined clit.

Her breath came in punched-out hitches. The headboard knocked a staccato rhythm against the wall. Some distant part of her brain registered the creak of his knees as he leaned closer, his suspenders brushing the small of her back. The vibrator's buzz synced with her pulse—a feedback loop of pain-pleasure that short-circuited coherent thought. Her thighs trembled like a diver poised at the edge of a cliff.

Harrison's free hand slid between her shoulder blades, pressing her flatter against the mattress. She felt the weight of his stare tracing the sweat-slick dip of her spine, the way her ass dimpled when her muscles tensed. The vibrator switched to a brutal, erratic pattern—the same rhythm his wife had liked, once. Lisa gasped into the pillow, fingers twisting in the sheets. "W-wait—" Her clit throbbed raw and hot beneath the silicone onslaught, every nerve singing with oversensitive agony. "Can't—too much—"

The vibrator didn't stop. If anything, the buzzing intensified, the ridges catching against her swollen hood with each pass. Tears smeared the pillowcase as she tried to buck away, but his grip on her hip pinned her in place. Harrison exhaled through his nose, watching how her cunt clenched around nothing with each forced pulse of pleasure. "Cycle's not complete," he muttered, nudging the toy harder against her twitching flesh.

Lisa sobbed when his other hand slid beneath her belly, palm pressing upward to tilt her hips higher. The new angle sent the vibrations ricocheting through her oversensitive clit straight to her g-spot, a feedback loop of torturous stimulation. Her thighs trembled violently, toes curling into the sheets. "Please, sir—" The honorific slipped out unbidden, voice shattered into static. "I'll—I'll be good—"

The vibrator clicked off. Silence rang in her ears louder than the buzzing had. Harrison's fingers lingered between her legs, tracing the swollen lips with something like scientific curiosity. His fingertip caught on her entrance, slick with fluids that weren't entirely arousal, rubbing the moisture between his fingers.

Lisa couldn't form words—could only nod into the damp pillow. Her entire pelvis ached, muscles fluttering in exhausted aftershocks.

"Christ alive." The pad of Harrison's finger pressed just inside, meeting resistance that made his wedding band dig into her pubic bone. His breath hitched at the velvet vice grip threatening to swallow his knuckle whole. Twenty years since he'd touched a woman, but he remembered the difference between tight and untouched. "You've never...?" His voice cracked like old varnish.

Lisa's shoulders hunched. The confession dripped from her lips: "Just—just toys." A mathematician's chastity—variables controlled, proofs neatly boxed. His fingertip withdrew, glistening with evidence of her body's rebellion against its own inexperience. She felt the cool air kiss her exposed entrance, the sudden emptiness felt more humiliating than his probing.

The bed dipped under Harrison's weight as he settled beside her. His knees popped in protest—arthritis waging silent war on stolen moments. Lisa rolled onto her back without being asked, legs falling open in surrender before her conscious mind could object. The movement stretched her sensitive flesh taut, her slit glistening awaiting.

Harrison raised his trembling fingers to his lips. The scent hit first—musky and sweet, undercut with something metallic like licking a battery terminal. His tongue darted out experimentally, collecting her essence along the whorls of his fingerprint. The taste bloomed across his palate with the complexity of old wine: a lingering sweetness that made his saliva glands ache. He closed his eyes as his dentures clicked against his knuckle, sucking gently to harvest every drop.

"Better?" His voice rasped like sandpaper on rusted hinges. The question hung between them, weighted with implications neither acknowledged. Better from the assault of silicone? Better from the shame of being caught? Better from the years of untouched solitude that had led them here? His thumb hovered over her inner thigh, smearing a stray bead of fluid that had escaped her trembling folds.

Lisa's breath hitched. Her clit throbbed in time with her pulse, oversensitive flesh still twitching from the vibrator's brutality. She nodded jerkily, the motion making her damp bangs stick to her forehead. The lie tasted acrid—she wasn't better, wasn't sure she ever would be again. Her thighs glistened with a mixture of sweat and her own slick, the musk thick enough to coat her tongue.

Harrison's suspenders creaked as he leaned closer. His nose wrinkled at the tang of sex and salt—an olfactory equation whose solution stiffened the arthritic fingers now tracing her hipbone. "You're dripping," he observed, voice detached as if commenting on rainfall. His index finger painted a wet stripe from her navel to her pubic mound, collecting evidence of her body's treason.

She whimpered when his hand settled between her legs, not touching but close enough that his wedding band chilled her swollen lips. The metal carried decades of patina—twenty years of absence, now pressing against flesh that had known only plastic substitutes. Lisa's hips jerked involuntarily.

Harrison's tongue surprised her. Not the tentative flick she'd imagined, but a broad wet stripe from perineum to clit that left her gasping. The texture was all wrong—smooth where it should be ridged, dry where it should be slick. Dentures clicked against bone as he flattened his tongue over her entrance, lapping at her juices like a man savoring the last dregs of tea. His nose bumped her clit with each pass, the cartilage colder than she'd expected.

He groaned into her, the vibration traveling straight to her nerve endins. Lisa's fingers twisted in the quilt as his tongue delved deeper—not probing, but mapping. She could practically see the calculations scrolling behind his bifocals: angle of attack, viscosity coefficient, frequency of her choked gasps. His chin gleamed with her wetness when he pulled back to breathe.

"Still sweet," he muttered, thumbs spreading her wider. The scrutiny burned worse than the vibrator had. Lisa watched her own juices string between his lips when he spoke, stretching thin before snapping onto her thigh. His tongue returned with purpose now, circling her entrance with military precision. Each pass teased the rim without breaching, collecting evidence of her body's betrayal.

The third time his tongue breached her entrance, Lisa's vision whited out. The intrusion was too much—too hot, too knowing—her walls fluttering around an appendage that...