Artist's upload: https://www.hentai-foundry.com/pictures/user/sabudenego/466204/Misc-Pic-009-Saeko-HotD/page/all

Story, I was able to get in contact with hdc and they gave me permission to post the full short:

The tall cop, Masao, groaned with pleasure as he sank his cock into Saeko's mouth. His thrusts were slow and deep as he savored the feel of her pink glossy wet lips sliding over his long hard shaft, most of which already glistened with a thick coating of her drool. More than once, she had nearly taken him to the hilt, but she couldn't quite manage it. Tears brimmed in her violet eyes as he struck the back of her throat and she gurgled frantically until he withdrew, leaving her gasping for air, with drool and pre-cum trickling down her chin and joining her mouth to his cock. She had been forced to her knees, her arms bound in a painful box tie behind her back; she was totally at his mercy, unless she bit him, and the consequences for that didn't bear thinking about.

As bad as that was, she was grateful that the shorter one, Osamu, preferred to fuck her breasts; his cock was even longer than Masao's, and there was no way she could have accommodated even half of him with her mouth. Her breasts were quite large, but with his length thrust between them, they seemed smaller. She shuddered at the thought of taking either of these men's shafts between her thighs, but she knew they would inevitably demand it. They, or one of their colleagues who were lined up to await their turns with her. Several of them already had their cocks out and were stroking them slowly as they watched her service her first two men.

Outside the fortified police station, the zombies roamed mindlessly. Their screeches and howls were faintly audible even through the thick exterior walls, and made an eerie counterpoint to the soft groans and grunts inside. Occasionally, one of the zombies clawed at the windows, pressing its rotted face against the shatterproof glass and staring blindly inside. The cops were used to this, and ignored them. For Saeko, they served as a grisly reminder of why she was doing this.

Takashi's group needed shelter. As they escaped from a marauding band of feral survivors, Alice was grazed by a spiked club and received a nasty gash across her thigh. The group had no medicine and nothing to suture with; Shizuka had cleaned and dressed the wound as best she could, but it had become inflamed, and now the girl was feverish. Taking a terrible risk, they sneaked across a deadly no-man's-land with zombies on one side and deranged survivors on the other to reach this police station.

But the cops here turned out to be little better than the ruthless gangs of survivors outside. Freed from the restraint of higher authority, watching civilization crumble around them, they had embraced their lowest instincts and now lived by plunder. People who could pay - in supplies or other valuables - were allowed to take shelter in the police station. Those who could not were turned away to die screaming under the claws and teeth of the endless zombie hordes.

Saeko was the point man; she approached the heavy steel door first. A small viewport opened and two small, piggish eyes inspected her. They gave her a bad feeling. They belonged to the short one, Osamu, as she later found out. The eyes lingered on Saeko's breasts as she argued with him. At last he mentioned to her that there were other kinds of valuables besides food and guns. His eyes rose to meet hers, to see if she understood. She ground her teeth at the thought of what he was proposing, but, inevitably, she nodded.

She told the others what she had agreed to. Appalled, they argued with her, but in the end, like her, they saw no choice. They could not possibly fight their way into the police station, not with the zombies at their backs. And so, reluctantly, they entered the station one at a time, surrendering their weapons. Osamu searched each of them, roughly, while Masao stood guard with his pistol drawn. Osamu especially enjoyed searching the women. Kiriko squirmed under his pawing and gave him such a hateful glare that Saeko was afraid she would attack him, but she restrained herself. Her obvious rage only heightened Osamu's enjoyment, and he spent quite a while with her.

Saeko could only pray he and his colleagues would not decide the bargain included Kiriko and the other women as well.

The police doctor was an old man with a shock of white hair and a lined face that, in the flickering candlelight, seemed to speak to Saeko of a thousand sins. He smelled of gin, and the way he eyed her suggested he expected to be paid in the same way Osamu was. His examination room appeared dingy in the dim light; with a flicker of horror she saw a small horde of cockroaches swarming over each other in one corner. But he had antibiotics for Alice's fever, and antiseptics for her wound, and a clean needle and suture thread. To Saeko's relief, he let Shizuka do the sewing.

Saeko was now on her knees in the squad room, fulfilling her end of the awful bargain. The others had been sent away. She was glad they didn't have to see this.

Her body faced Osamu as he fucked her breasts; her head was turned to her right so she could service Masao. Her neck and jaw ached furiously; she thought she would almost prefer the next man to use her vagina rather than her mouth. She closed her eyes and sucked hungrily at Masao's cock as she rubbed her chest against Osamu's hard length. Her breasts were pressed against the front of his uniform trousers, suspending them in place even as her body moved up and down.

At first, Masao and Osamu exchanged good-natured ribbing about which part of her felt better. Osamu eloquently described the sensations of having his cock trapped between Saeko's lush breasts, while Masao retorted that they couldn't possibly compare to the feel of her warm wet mouth. A flush of humiliation and anger climbed Saeko's neck into her face. Secretly, she enjoyed inflicting pain, an urge she had learned to firmly suppress, but she had rarely met people she wanted to hurt this badly. And they were only the first. As best she could, she channeled her mounting anger into sucking and grinding harder, so she could get this over with sooner. At last, the two men's banter died down, replaced by harsh breathing and deepening groans of enjoyment.

Osamu came first. He gripped her breasts tightly in his calloused hands, crushing them against his cock. Saeko was struck in the side of the face by a thick rope of warm semen, which was quickly followed by another, and another. By the time he squeezed out the last of it, she had received a generous coating of cum; it clung to her hair and dripped from her nose and ear and chin and glazed her breasts and pooled in the folds of her ripped top.

The sight of it drove Masao over the edge. She was afraid he would finish up by driving his cock down her throat, but instead he pulled out and added his release to the mess that spattered her face and hair and breasts. It was good her eyes were closed, because a thick glob of semen struck her in the right eye; soon it congealed into a sticky paste and she was afraid to open that eye from then on.

It was then Saeko heard the other sounds. Masao's and Osamu's gasps and groans of ecstasy had drowned them out. The sounds came from one of the nearby rooms into which her friends had been herded. One of the sounds was a wet, rhythmic slapping that echoed from the walls. Another was a continuous low moan; it was thin and muffled and Saeko noticed it was interrupted by each of the slaps. Finally, more clearly, she heard the sound of someone sobbing. It was Rei.

The line of men waiting for Saeko was noticeably shorter. Clearly, some of them had become impatient.

Saeko's large violet eye looked up at Osamu, a look of anguish and accusation and betrayal. He smiled at her and gently ruffled her sticky hair, then stepped back to make room for the next man.