Primal Ch. 01: The Rut

It was the start of the rut again. Sienna could feel it —that same old distinctive ache in her body, often warm or even hot to the touch, particularly concentrated in the depths of her womb where it radiated outward to the her sex and up through her breasts to her nipples.

Sienna absently ran her hands over them, kneaded them, felt how heavy and swollen they were and how veins — some of them visibly engorged — crisscrossed the rosy skin like a haphazard spidersweb. She felt it — the need, the intense desire deep inside her to submit to a bull, breed, carry his young, watch her belly swell and her breasts grow heavy with milk, until it was time for her to give birth in nine months.

Standing before the broken mirror, she stared at her reflection for a while. Then —with force of will — she sighed, dropped her arms, and shook her head. She had resisted the urge for years now, and she would do so again this year.

Every fall, the population of humans on Gaia III fell into the rut, the breeding season where the majority of fertile hucows went into heat and their male counterparts faced a somewhat more intense drive to roam and impregnate as many as possible. While, for the most part, nearly identical to the original humans of Earth, Gaians had undergone centuries of selective breeding and small genetic alterations. The most obvious difference was the sexual dimorphism — Gaian males, or "bulls," are typically more muscular than Earth humans and only occur in roughly one of every ten to fifteen births; while Gaian females, or "hucows," display more pronounced sexual features and a higher tendency to produce multiples of young.

Sienna was a prime example of this. In her "herd" — a group of seven hucows and the occasional wandering bull — she was a prized hucow, evidenced by a fertile curvaceous figure, wide slow hips and large full breasts perfect for feeding calves, as well as her belly, which had an attractive softness, but remained always flat. Sienna never allowed herself to be bred during the rut. Like most healthy hucows, she had gone into heat every year, but she didn't want children and turned the bulls away.

That wasn't unusual, but most Gaians didn't deny the rut. Aside from the intense sexual urges, Gaians valued the rut because of their small and declining numbers. Bulls competed for hucows, but they rarely killed each other, because producing young, any young, to continue the species was paramount and Gaians dying, any of them, hurt the greater good. Just like bulls, the hucows placed the future of the herd above everything else.

It remains a mystery why humans on Gaia were altered, or why they were on Gaia in the first place. The records were lost, as presumably most of the Gaians were, during a catastrophe in the distant past that left their planet a ruin, filled with empty ghost cities and overgrown wildernesses that hadn't seen sentient eyes in decades, if not centuries.

Sienna stood in the ruined husk of some ancient apartment building now. All the windows were blown out. Black scorch marks dotted the walls. Jagged cracks had formed in the ceiling. And on every conceivable item and surface was a fine residue of dust. It covered everything.

Her herd was settling down in the building as shelter for the night as they pressed eastward in their never-ending search for better pastures. As Sienna stared at her reflection in the broken mirror, she found her hands wandering up to message her aching breasts again and again she forced them back down with a huff.

Behind her, she heard a chuckle.

A blonde-headed hucow, Neera, came into view and shook her head with a bemused smile as she chuckled at her friend's predicament.

"Seriously, Sienna," she teased. "I can barely stand to look at you right now. Just let a bull mount you and put his baby in you."

Sienna cocked an eyebrow and gave Neera a warning look. It didn't escape Sienna that Neera was also in heat, judging by her own swollen breasts and the rosy flush in her cheeks and throat. She looked a bit feverish, with a faint sheen of sweat on her pale skin like she had just spent an afternoon in the sun. All of this could be clearly seen. Both hucows were naked, as Gaians had never felt the need to wear clothes on their tropical planet.

"Really, Neera, leave her alone," came the voice of Sienna's fraternal twin sister, Ivy. "If Sienna doesn't want to breed, then she doesn't want to breed, and it's as simple as that."

Ivy followed her voice into the room, carrying a six-month old calf on her hip as she glided in. Her breasts swayed, pendulous and heavy with mother's milk. It would only be a short time before the calf sleeping against her side, Medina, needed to eat.

She gave Neera an admonishing look — not all that different from the one her sister shot from the mirror's reflection.

"Sienna's her own woman. If she doesn't want to be a mother, that's her choice," she said. "It doesn't do anybody good if a calf is forced on a hucow who doesn't want them. If it's meant to be, Sienna will come around in her own time."

"I'm just saying that, instead of suffering through the rut, Sienna could give in and get it over with for a change," Neera said with a shrug. "Being bred isn't exactly a horrible experience, either. A good bull could do wonders for you."

"Maybe I'm just looking for the right bull," Sienna said. "Have you ever thought it might be that?"

"Hmmmm," Neera murmured, unconvinced. "Sounds like an excuse to me."

"Maybe you should concentrate on finding a good bull of your own and leave Sienna to her concerns," Ivy said. "At any rate, we haven't seen a bull in more than three weeks, so there's nothing to be done about that either way."

Neer pursed her lips thoughtfully and her deep green eyes glinted. Her hand snaked down to her slit, where her vulva looked puffy and red.

"We'll see. It's still early in the rut."

"It's probably not the best time even if I did want a calf. We don't know when we'll find a good place to settle down again, and it's hard enough for Ivy and Yvette to keep up with little ones to look after."

"It's no trouble at all," Ivy lied, contradicted by her tired smile and the bruised shadows under her eyes. Drops of whitish fluid formed on her fat nipples, areolas darkened nearly black since early in her pregnancy. "Medina is more than worth it. Calves are our future. We always find a way."

"You look like you could use some sleep," Neera observed. She leaned in and kissed Ivy on the cheek and started out the door, saying as she went. "I'll go prepare you some bedding for the night."

Ivy and Sienna watched her go. Then — after a pause — Ivy walked to the door, looked around, and returned to Sienna. Hoisting Medina with one arm, she reached out and took her twin by the hand with a squeeze.

Sienna gave her a quizzical smile.

"You always have that look when you're about to ask for a favor."

"I am," Ivy said in a quiet voice. "I'm not staying here. Not tonight. I need to sneak out while the other hucows are asleep and you need to help me do it."

"Why in Gaia do you need to keep this from the other hucows?"

Ivy giggled. "Because I want to keep him all to myself."

Things were starting to make sense for Sienna. She leaned back a little and crossed her arms over her chest.

"Ivy," she whispered. "I had no idea. Only six months after Medina was born? You're in heat?"

Ivy nodded. "I lied about not seeing a bull for weeks. We have run across one, you just never realized it. He found me while we were passing through the old subway system, near the old travel kiosks."

Sienna actually laughed. "And, what? He's still there? During the rut?"

"I convinced him to keep quiet. Let's just say I have a personal connection to him —it's Medina's father."

Sienna's eyes widened. "Logan? Logan's here?"

"I know, I thought he was far, far away, too," Ivy said. "As it turns out, he's headed to the same place — the city on the hill the others talked about —and he happened to overhear us passing through the subway. When he spotted me, he couldn't resist ."

"But, Ivy, now? Medina's not even a year old, and you want another?"

In answer, Ivy held up Medina, as if she was some self-evident proof.

"Look at her," Ivy said with obvious pride. "Would you need another reason to want another calf sired by her father? I've never met a stud bull who compares to Logan. Maybe you'll understand someday, but the feeling of a bull mounting you, dominating you as he drives his cock into you and plants his seed inside you...it's incomparable, Sienna."

Sienna eyed her sister thoughtfully for a while, neither twin speaking, as she weighed the situation in her mind. Eventually, she nodded and shrugged with resignation.

"Fine. If this is what you want. I won't try to stop you," she said. "You're planning to meet with Logan tonight?"

Ivy gestured out the open window darkening with sunset.

"There's a shopping mall complex to the south connected to this building through a skyway. He's agreed to meet me there this evening."

"Okay," Sienna said. "We'll sneak you out then and I won't breathe a word to the others. That's what you want, right?"

Ivy gave her that look again — the one she always had just before a favor was on the bargaining table.

"I need you to come with me, Sienna. Somebody has to look after Medina and I don't want to walk through the dark alone in a strange colony. I'll find a way to repay you twice over, I promise."

Sienna cocked an eyebrow and eyed her sister dryly.

"Oh, you better. You better believe I'm not letting this one off for free."

Swaddled in a small bassinet, Medina didn't make a sound, content to look around with her big inquisitive eyes and take it all in.

Sienna thought of Medina's birth six months before. As Ivy's sister, she was the one who held her twin as she pushed and pushed for what seemed eons. Ivy was the picture of womanly fertility then. Sienna remembered how, at one point in the labor, her sister got down on her hands and knees, and how her milky tits hung heavy beneath her heaving chest, dwarfed by the huge belly that nearly touched the floor. She arched her back and presented her pussy, pushing and pushing until Medina crowned for the first time.

These thoughts Sienna occupied herself while she waited. The alternative was listening to her sister mating with a bull in the next room over. Ivy was gasping and moaning in a jarring rhythm as Logan rutted, gaining intensity, until Sienna could hear his deep throaty grunts faintly.

Admittedly, Sienna was a little curious. She had heard a lot and caught glimpses of Logan, but never met the impressive bull for herself. Ivy hogged him all to herself, which left little more than rumors for Sienna.

Ivy moaned loudly. Sienna glanced at Medina, glanced at the door to the room occupied by Ivy and Logan, then glanced back at her niece. She bit her lip and considered her options.

It wasn't far. Just a peek.

Tiptoeing to the door, Sienna cracked it open a little further and peered in.

Inside was a front-row seat view of Logan's ass. Taut muscles rippled beneath his skin. Logan was fucking Ivy on a table, standing with his arms outstretched, gripping Ivy's ankles so her legs formed a V while he pounded his cock into her pussy at the nexus.

His scrotum hung low and leathery and weighty, a little bloated and veiny with the rut. While Sienna watched, Logan thrust vigorously, over and over, while the sack slapped against her sister's cleft and his testicles gradually pulled up and tightened against his cock.

Ivy sat up, pressing her fat tits against his chest and Sienna spotted a streak of whitish fluid dripping down Logan's torso and legs as he kissed her on the mouth. Milk. Her sister's erect nipples were trickling milk while Logan fucked her and built toward a climax.

Sienna let a faint moan escape before she slapped her hand over her mouth in slack-jawed astonishment. This was torture. At the sight of her sister being bred by Logan, her body ached as it rarely had before. She found her hand drifting down her tummy, past her belly button, to her pussy.

Logan leaned forward and pressed his lips against Ivy's throat as he clutched her breast in his hand, as if to weigh its weight in milk, and shifted his body into slower, deeper strokes. His balls were tight against his cock now, riddled with livid veins and churning with cum.

"Ivy," he rasped in her ear. "Ivy, I'm nearly— "

In answer, Ivy reached around and clutched his ballsack, using her delicate little fingers to knead his heavy testicles as if to coax them into flooding her womb with sperm.

And he did. Logan snarled and thrust hard with the entirety of his frame, forcing his cock hilt-deep into Ivy's vagina as his balls emptied themselves in a series of throbbing, convulsive pumps. Even from where she was, Sienna could see the contractions at the base of his scrotum and how the channel bulged the length of his member as he bred Ivy.

Panting for breath, both of them came down the heights of ecstasy and smiled. Logan ran a hand through Ivy's black hair. She kissed Logan at the base of his throat. They sighed contentedly.

Logan straightened to his full imposing height and stepped back, pulling his softening member out of Ivy's pussy. Eyeing her up and down, Logan flashed a lopsided grin and reached down, cupping one of Ivy's engorged breasts in the palm of his hand. It overflowed his fingers and he was rewarded with a little spurt of milk.

"You're even more bountiful than when I bred you the first time," he murmured approvingly. "Motherhood suits you well."

"Why do you think I came back for seconds?" Ivy replied, still panting.

"There's more where that came from," he said as he slowly turned and started for Sienna's door. "Do you want anything? I'm parched and I think I'll take this opportunity to introduce myself to my daughter."

Suddenly aware of her precarious position, Sienna barely had enough sense to scamper away from the door and back to Medina's bassinet before the door slid open to reveal Logan.

Sienna did her best to pretend she was preoccupied with caring for her niece, but it was painfully obvious she was still hot and bothered by Ivy's breeding. A burning flush — half embarrassment, half sexual arousal — colored her body a rosy red, which accentuated her aching tits and her engorged slit. Nobody was fooled.

For his part, Logan sauntered into the room and spotted Sienna, flashed a surprised expression on his face. Wild hair — maybe a little overgrown, due for a haircut — was plastered across his brow and fell into his eyes.

"Oh," he said, seeming genuinely taken aback by her presence. "I didn't realize you were there. I hope I haven't startled you."

Sienna struggled to come up with something normal to say, but Logan looked her up and down, shot her a knowing smile, and chuckled.

"You look absolutely miserable," he said with sympathy. "It just never goes away. The pressure. The ache."

Between his legs, Logan's manhood hung at half-mast, still a little hard after his breeding with Ivy. Sienna observed his testicles remained swollen and tender, full of cum, despite filling her sister with enough sperm to father a litter of children.

She swallowed. Her throat was so dry it hurt a little. She managed a nod.

"Yes."

Logan sighed and lowered himself down onto a pair of empty crates propped up on each other to serve as a chair. His cock hadn't lost its stiffness and Sienna thought it had actually grown harder again, thicker, while the head slid out, re-emerging from its foreskin sheath, and a bead of precum formed on the tip.

"Sorry," Logan said. He gestured vaguely at the opposite side of the room. "I'm practically dying of thirst over here. Could you find my satchel. I should have a thermos in there with water, if you could bring it to me."

Sienna obliged and searched around an alcove with a window facing out into the darkened ghost city. There she found a worn old leather satchel, in which Logan kept all of his belongings during his endless travels. Inside, nestled between a folded blanket and implements to start a fire, was an old metal canister from the days before the mysterious catastrophe.

Sienna picked it up and gasped. It was cold. Frigid to the touch.

Logan nodded.

"Amazingly enough, there's still functional refrigeration units out there if you're lucky enough to find them."

Sienna walked over and handed Logan the canister. Muscles bulged and flexed rapidly along his bulky shoulders and arms as he gripped, twisted, and popped open the tightly sealed thermos in a single motion to reveal clean water inside. He threw his head back and drank deep. Some water escaped and ran down his throat in rivulets.

When he was done, he found Sienna eyeing the water as if entranced — which wasn't all that different from her fixation with his hardening cock.

He smiled with good humor and offered Sienna the thermos.

"Here," Logan said. "Take a drink. You look like you need it."

Eagerly, Sienna reached out and took the canister. As she drank his water, Logan eyed her up and down, taking in her exceptional physique, a perfect hucow body built to create and nurture life within that boxum frame, the wide sloping hips, a plump bubble butt, and her large firm tits, which seemed to contradict her smooth round tummy.

"You're Ivy's sister, aren't you," he observed. "Is it Sienna? I can see the family resemblance. She's told me a lot about you."

"Oh?" Sienna said. She wiped her mouth with her forearm. "What did Ivy tell you?"

His gray eyes narrowed a bit.

"Not half as much as I've heard elsewhere. You've got a little bit of a reputation. Many of the bulls I've run across speak highly of you. I'm sure you know you have a small throng of men who'd like nothing more than to get on your good side."

"That's because I don't give them what they want. It's strange how denying people is the best way to ensure they want you all the more."

If Logan heard her, he made a point of ignoring that last bit.

"So, if you were ever to breed, what would you want? A boy, or a girl?"

If Sienna heard him, she made a point of ignoring his question.

"I should check on Medina," she said as she turned and made her way over to the infant's bassinet, her smooth ass swaying, giving a peek of the vulva between her thighs. Logan smiled to himself, stood, and followed after her.

The two of them stopped by the bassinet. Logan watched over Sienna's shoulder as she leaned down and intertwined her finger with Medina's tiny little fist. The baby was dozing peacefully. Both adults beamed down at her.

"She's beautiful," Logan murmured in his deep reverberating voice. "Just a few minutes of passion and it creates something so wonderful. I can't put it into words, just how mysterious and humbling it is."

"She is beautiful," Sienna said in agreement. She turned and searched Logan's face, down at Medina, and saw a resemblance in his smile. "I think Medina inherited your smile."

"Just a tiny contribution," Logan said, dismissively. "She comes from good stock. Ivy is a prized hucow and a good mother. That's where Medina gets it."

He glanced over at Sienna, standing little more than a foot away. Her breasts heaved slightly as she breathed in and out while she watched him intently. Her eyes flashed in the subdued light of the room.

"Medina is a beautiful calf because she comes from a family of beautiful hucows. I'm sure you'd breed cute babies, Sienna."

Sienna glanced down at his cock, fully erect, powerful, with the head and shaft rearing out of the foreskin stretched tight and taut. His leathery sack swayed beneath it, hanging heavy and low.

"I'm sure you'd breed a lot of them," she said.

Just then, Medina gave a fussy wail from her bassinet and Sienna whirled around to tend to her. She felt Logan's cock inadvertently brush against her thigh and ass cheek, radiating heat as it left a smear of precum on her skin.