Chapter 0

“Hngh…!”

Erin slowly closed her eyes, then opened them again.

It felt strange that such a cracked voice had come from her own throat. And that wasn’t all.

“Th-this kind of…”

The heat consuming her body, the sensation of sweat sliding down her bare skin—everything felt overly stimulating to her. Everywhere that dampness spread, it felt as though blossoms of heat flared up.

“This is too…”

But the most stimulating of all was—

“Ah!”

The mercilessly overwhelming sensation of being broken down, licked, and sucked.

The man’s large hands and lips that tormented her peak, pushing her reason right to the cliff’s edge.

“W-wait! Ash!”

“Stay still, Doctor.”

“I, I thought about it and… this is unnecessary after a—”

“No.”

His growl-like voice cornered her, telling her to stay put. Because he spoke with his mouth pressed to her sex, his hot breath rushed inside, making her shudder and try to close her legs.

“That’s your opinion, Doctor.”

Flustered, Erin reached down between her thighs and pushed against the man’s head, trying to push Ash away.

“Ash…”

True to his name, his ash-gray hair looked even darker in the dim light. Each time Erin’s fingers moved, his silky strands spread beneath her touch.

Startled by how soft his hair was, she twitched—and below, his red eyes met hers with a sultry gaze.

Flutter.

His long lashes brushed past her mound. Then his high-bridged nose burrowed into her peaks.

“Ah!”

Even this obscene act looked too beautiful on him, leaving Erin momentarily speechless.

Ash, seeing her dazed, narrowed his eyes with a faint smile. Then he pulled away the hand that was pushing at him and kissed it.

The overly intimate gesture made Erin jump.

“T-this kind of thing…”

“It’s all necessary. So…”

“Hhh…”

“Don’t move.”

Or you’ll get hurt.

Though he spoke politely, the words felt like commands to her ears.

He always seemed mature for his age, but today, Ash felt as though he were her superior.

But he was her assistant, and she was his doctor. She was supposed to be the superior.

How strange.

But Erin didn’t have the capacity to think deeply because Ash had buried his face back into her sex.

“Hhk!”

Her legs splayed under the assault. His hot, pliant tongue traced her folds and licked her deeply, making her trembling body quake.

“Ah, nngh…”

Ash soothed her by sucking firmly at her sex, while his hand rose to cup her breasts.

Even while forcing her body with such overbearing dominance, his touch was soft, as though anointed in oil. It raised goosebumps.

Feeling his palm kneading her breasts, Erin thought, ‘His hands… were they always this soft?’

He always wore gloves in the lab, so she never noticed.

Even when they had been intimate before, she hadn’t paid such close attention.

Ash’s bare hands, cupping her breasts, were surprisingly big and sturdy, with prominent bones and veins—hands you’d expect from a fighter, not a lab assistant. Yet his palms were soft, his fingers firm.

Between them, her pink nipples had grown stiff, clear evidence of her arousal.

“Nnngh…”

His finger, adorned with a ring, twisted around one nipple. Each time the cold metal brushed her hardened peak, she flinched. Her eyes drifted to it.

‘…Looks expensive.’

Too expensive for a research assistant.

The band was thick, and the gem embedded in it—a deep, reddish-pink stone—looked like a ruby.

‘A ruby ring?’

Even amidst sweat and heat, the thought pierced her mind.

‘How can he afford something like that?’

Her lab barely paid above minimum wage—she had barely escaped exploitation herself.

Yet here he was, wearing something so costly.

‘Ash… Is he working for someone else too?’

Her scattered thoughts halted when the man between her legs spoke again.

“You’ve been so still—I thought maybe you were finally listening to me.”

“Nngh?”

“Your concentration is terrible, Doctor.”

“Hhh, ah…”

His tongue scolded her with firm licks. No longer just teasing the surface, he pressed deep into her folds, curling against her clit. Erin jolted as though burned.

“W-wait, wait! That’s too…”

“You can’t treat something this important so carelessly.”

“I, I’m not being carel…”

“And lying is even worse.”

He flicked her clit sharply, as though punishing her.

“Ah!”

The sudden surge of pleasure made her head fall back, her body arching. With it came a rush of wetness, gushing uncontrollably.

Blushing furiously, Erin stammered, “D-don’t…”

“If you’d focus, this wouldn’t happen, Doctor.”

Ash sighed into her depths. She flinched, and he nipped her thigh, speaking again.

“Still, it’s not so bad.”

“W-what…”

“Since you gush and get so wet.”

“…”

“Seems like no more foreplay is even necessary.”

His blunt words left her stunned.

Then Ash raised his head.

Her breath caught. His entire face was wet. She didn’t need to ask with what.

Shame burned her lips, but she couldn’t look away. His damp hair clung around eyes that gleamed even darker, and his soaked face was unbearably sensual.

Blink.

Each time his long lashes closed, droplets clung and fell.

When one drop slid down to his curved lips—

Lick.

He licked it away casually. Erin shivered. Her body heated even more at the sight.

“I always think this, but it’s amazing how sweet you are, Doctor.”

“D-don’t say things like that…”

“Right. That’s not what’s important right now.”

And with that, Ash stood and unbuckled his pants.

Thunk.

The heavy thing sprang free, filling her sight.

Gulp.

Erin unconsciously swallowed at the sight of the monstrous thing. Contrary to his delicate and sensitive-looking face, the surface of his curved penis was full of bulging veins. It always  seemed to be something that was too difficult to take inside her.

However, Erin knew well how easily it could enter her and how much seed it could spew inside her.

Her body, already heated, clenched in anticipation. Ash caught it, smirking.

“No need to beg. I’ll put it in, Doctor.”

“T-that’s not…”

“And I’m going to come inside you.”

As he rubbed her lower belly, he pressed the swollen tip against her entrance, teasingly stroking her folds and clit. Her hips jolted.

“Hhh… ahhh…”

“So don’t worry.”

“A-Ash…”

“Even if you don’t squeeze like that, all of my seed is for you.”

“Don’t say it like that!”

“But Doctor—that is the contract, isn’t it?”

He grinned, cupping her heaving breast. Satisfied by its softness, he sighed lazily and licked his lips.

“To come inside you until you get pregnant.”

Erin jerked in shock, shaking her head quickly.

What was he talking about!

“O-our contract doesn’t say that…”

“To keep fucking you and coming inside you until you finally carry my child.”

“It’s not…!”

“Ah. Was it the other way around?”

Ash spread her thighs wider, hooking one leg over his shoulder. His length rubbed insistently at her entrance.

“You’re right.”

“Uhk!”

“It was the other way around.”

Still smiling, he pushed forward.

Thwump.

The penetration was sharp and sudden.

“Ahhh!”

Her breath tore out as he filled her to the hilt. Inside, she clenched tightly, her walls spasming as if to crush him.

“Kh…”

Ash grunted, rubbing her clit to soothe her. But her trembling walls didn’t relent, making him grit his teeth and start to thrust.

“Hh, ahhh!”

Her pale skin rippled with every movement, sweat flying. Pleased, Ash gripped her waist firmly, breathing raggedly into her ear.

“Hhh, uhk!”

Heat flared in her ears. Erin whimpered.

“Ahhh, Ash… it’s too deep…”

“Of course it’s deep, Doctor.”

“Nnghh…”

“I have to reach your womb—to fill it.”

His low laugh made her walls convulse again, beyond her control.

“You can’t let a single drop spill.”

“Ah, ugh…”

“You’ll take it all, right?”

His crude words only heightened her arousal. She clung to him with trembling legs.

“…Hah.”

And suddenly, warmth gushed inside.

“…Ah?”

Erin’s eyes widened.

‘Huh?’

He was spilling into her much earlier than usual.

“W-wait, Ash, I-I’m—!”

But even as he came, Ash didn’t stop thrusting. He didn’t look the least bit flustered.

Squelch, squelch.

White clumps spilled out around their joining.

Already overloaded, Erin’s vision went white as another climax tore through her.

“You’re wasting it, Doctor. Clenching and spilling like this.”

“Ahh, nnngh!”

She wanted to protest—No, it’s because you came too much!—but her words dissolved into broken cries.

Ash sighed, shaking his head.

“This is what you asked for. What a waste to throw it away.”

“A-Ash. Ohh…!”

“I have no choice… I’ll just have to come again.”

The relentless flood of sensations felt almost violent. Erin’s body burned.

“Ahhh…”

Her whole body trembled, pinned beneath him. His low chuckle vibrated through her.

When she reached out blindly, Ash caught her hand.

Then he pressed light kisses to her fingertips.

“We’re not done yet, Doctor.”

“W-wait…”

“You have to show the results of the experiment, don’t you?”

As if the semen already filling her wasn’t enough, Ash thrust his hips and laughed again.

“That even if I come inside you dozens, even hundreds of times… it’s impossible for you to get pregnant from my seed because of your medicine.”

“Hmph!”

“You have to prove that, don’t you?”

No matter how many times—the words made her dizzy.

Thwump!

Inside her, he swelled hard again. Erin gasped.

Right. That was their contract.

‘To prove… no matter how many times, I can’t get pregnant…’

And so, here she was, taking her assistant’s seed again and again.

The realization struck her.

The fact that it didn’t cool her body but instead lit a hotter fire within her was a little embarrassing.

Each time Ash squeezed, pressed, and thrust, her senses screamed at their limit.

“Nnngh, nnngh!”

Her flickering reason gave way to heat as her vision blurred.

‘Right. So… How did things end up this way?’