"Feel the difference, James," said Sean. "He has a somewhat harsher touch, but very agreeable."

James closed his eyes and felt the black lad's lips sliding up and down his member. He caressed his ears and felt the curly hair on his skull; he was hard again, and ready to cum. He glanced at Sean interrogatively: Sean nodded, and James began to fuck the centaur's mouth with quick, forward movements. He came again and watched as the centaur obediently swallowed his juice. "How did you get him to do this?" he whispered to Sean.

"Sac ring," said Sean, in an equally low voice. "Very persuasive..."

James smiled. Sean had gone under the young male's body and was caressing his cock, which stretched out to full length. He approached and began to lick the thick, long black shaft. Kafu closed his eyes and let his master do what he wanted to; Sean's tongue slid over the head of the cock, feeling veins and skin shivering with his caress.

"He tastes divinely," he said as he felt his urge satisfied.

"Yes, he is healthy..."

Kafu opened his eyes; his cock was stretched out and quivering with unappeased lust.

"Cool off, my friend," said Sean. Then he saw Beau passing by the stall. He had an idea:

"Or better... Beau! Come here!"

The mulatto girl entered the stall. Sean made a gesture for her to take off her pants and took the measurer from his pocket: it showed seven.

"Good girl! I see you have not touched yourself. You will be rewarded: Kafu here will please you. Come here!"

Beau put her hands to the bar and bent herself into an almost ninety degrees angle, exposing her pussy to the men.

"Kafu, you will enter her gently... And hold your cum until I say so, understand?"

The colt was panting with lust, his cock stretched out. He went near the girl and put is front legs up, letting them rest on her shoulders; Beau went a bit down with the taur's weight, her hands firmly clutched to the bar. Kafu found her hole and entered it: she moaned as the rock hard cock slid into her. She began to rub herself against it; she was very horny, and she needed desperately some relief after all those days with the ring on her pussy.

Sean and James watched her perfect brown body shaking as she came on the colt's cock; she was ready to leave him, but Sean wanted them both to obey his commands.

"Quiet there, Beau! And you too, Kafu!"

The centaur was holding his breath; he too was ready to come, and it was with a visible effort that he held his spurt. Sean went under him and caressed his cock; then he rubbed his finger over Beau's clit, letting her feel the tip. The girl moved her hips in circles and groaned; Sean tugged gently the small chain that was dangling from her ring.

"Be obedient, Beau! Stay firm here... I want Kafu to have his time."

"Master, I have to do it!" Kafu's voice was tense with anxiety.

"Hold it! And move very, very slowly! Or the bug will bite you again!"

Kafu did as he was told. His cock ached with the need to come, but the memory of the pain on his sac made him very docile. He slid forth and back in the girl's wet pussy, feeling the cum on the tip of his member. Then he heard the man's voice:

"Go!"

He released instantly his load into Beau's cunt. It was his first time; he had never felt such a good sensation. He kept shooting and gasping, holding Beau's shoulders with his hands, gently licking and biting her ears as if she were a centauress. Beau was shaking her body, trying to stop the cock from moving in her pussy, because she was already pleased and was getting uncomfortable. Sean grabbed the end of her chain and tugged it.

"Quiet there, girl! Let him do as he pleases, he is a male!"

Beau felt the sting on her labia and stopped moving. Kafu slowered his movements as his penis got flacid inside her; then took out his cock from her; she stayed on the bar and felt the point of the measurer touching her lips.

"Two," said Sean. "This means she had enough pleasure for one day. You may dress up now, Beau. Thank you, you are a lovely girl!"

They left the stall and walked back to the house. It was getting dark and dinner should be served soon: another day had passed, with its harvest of profits and pleasures.

23. Under the belt lock

That night Linda slept very badly. She kept waking up every hour or so; the tension in her clit was becoming unbearable, as the effect of the centauress cream was still strong in her organism. She had got used to being pleased two or three times a day by one of the girls she had trained; now she was expected to stay longer and longer periods without any pleasure! She tried to pick the lock with a needle, but failed. As she got up next morning, her face showed tiredness and rage. At breakfast, as the usual jug of centauress milk was brought to their table, she addressed Sean:

"I will give up, Sean. I cannot bear this any more."

"Linda, please don't," said the farmer, his eyes gleaning at the prospect of having that drenched cunt milking his cock. "You have still fourteen hours to go. Do not disappoint me... I promise that you will get relief!"

James took a deep gulp of the still hot milk. He had loved having the girl's ass the former day; he couldn't help agreeing with Sean – life in the farm was becoming more and more agreeable to human males.

Linda sighed. She was being defeated, she could feel it. She consoled herself with the idea that the sensation of coming would be much stronger when her boss unlocked her. She smiled faintly:

"You are a devil, Sean."

"You will get used to being horny, dear. Think of Beau: she is also feeling lust, but she has not a belt to help her keep out from disobeying. I can imagine her dying to touch herself, and yet restraining from it. Or else..."

"Else what?"

"Else she will get belted. And I would not open her after a day or two... By the way, I think it would be interesting to measure you both after the same period of restraint: both of you have been pleased yesterday. Go to the lab and fetch her; I will be there in a minute."

Linda shivered. She had not told the mulatto girl about her belt; now that would be disclosed. She felt her face hot with shame.

"But Sean... she does not know about the belt..."

Sean's voice had an acid tone as he replied:

"Linda, if you say another word about this, you will be left locked for three days in a row. Now, go!"

Linda stood up without a word and went out of the dining room.

"She is hard to tame, but she will get there," said Sean.

"Her ass is something..." retorted James. "Have you tried Beau's?"

"Not yet; I am letting her ripe for some days before I try her again."

"I have been thinking," said James. "Her DNA has some traits in common with the tauresses, so her cream must have more or less the same aphrodisiac properties. What if this is true of other of her race, too? We could conduct a more ample experiment, injecting some ebony girls with a concentrate of tauress cream, and then using their secretion on other women's cunts. I suppose that it would not replace completely the tauress cream, but perhaps it could work as a secondary source of arousal."

Sean smiled. His associate's ingenuity was endless, he thought.

James went on: "We will spread some of Beau's secretion on Linda's clit and see what happens. Let's go!"

They went to the lab, where Beau and Linda were already waiting for them. They were told to undress; Beau opened her eyes wide at the sight of the white girl's belt. So it was true, she thought: that thing really existed, and they had put one on a white girl! She touched her pussy ring, but quickly took her finger from it, fearing that they could make her wear the belt if she disobeyed the order not to touch herself.

Meanwhile, James had cuffed Linda's hands behind her back and opened her belt. The scent of her pussy filled the air; the biologist rubbed his finger on her slit and tasted it. Linda moaned as she felt the fingertip rubbing her swollen labia, but James was not impressed.

"You taste deliciously, dear..." He measured her clit tension: it was near the maximum again. Then he turned to Beau, cuffed her hands in the same way and measured her, tugging slightly at her pussy chain, which was dangling from her ring.

"Also very horny, you, eh?"

He turned Beau's ring to maximum. The girl moved her hips savagely, her eyes turning in their orbits, trying to rub her thighs against one another.

"Quiet, you! I have to scoop you." James took a spatula and collected a good amount of the juice dripping from Beau's cunt. Then he went to Linda:

"Spread your lovely legs, dear..."

Linda looked at him, alarmed, but complied. James put some of Beau's nectar on his fingertip and rubbed it gently on the white girl's labia. Linda moaned and tried to resist; she knew that the juice would turn her on still more. James slapped her ass cheek:

"James, please..."

"Stop that!" He proceeded to lock her up again and uncuffed her hands. "We are going to test the effect of Beau's nectar on you. You can go and take the day off; next opening is tomorrow, this time." He turned to the mulatto girl:

"You can dress up. Please go to the Cream Factory and see how the mares are doing. We have a command for twelve ounces of cream from California and I would like to ship this tomorrow morning."

Beau obeyed and went off. Linda buried her face into her hands. She heard Sean's voice:

"This will last for only some weeks, dear. Then you will be released to be fucked and licked as much as you need! But please stop being a child, we are doing science here."

Linda sighed and went to the desk to check which mares should be covered in the next days.

In the enclosure, Beau had called Pedro and Jorge to prod the mares towards the Cream Factory. They had been chained from their necks in groups of three and four, and their bodies were tightly pressed to one another, as they marched in a compact mass.

"Whooaaa! Quick you go... You there, don't move away from the herd!" Pedro shouted.

"Fine animals, aren't they?," said Jorge as he walked by a particularly elegant mare. "Mr. Parker could let us try them once..."

"Yes, that would be fine," said Pedro. They arrived to the Cream Factory and linked the mares to the hooks on the walls; the flasks were attached to their pussies and Beau turned their rings on. She watched their bodies begin to shake as the stimulation on their clits went up and up; soon their cunts were wet and the precious substance was dripping into the flasks; the three new fillies were also attached, thumping the ground with their legs in an unsuccessful effort to get relief from the itching under their tails.

Some of the mares had a capital C on their earrings, marking them as especially abundant producers of cream. These were drained daily for one or two hours, after the mandatory milking of their breasts and before being sent to the fields or to other tasks; the others were less frequently brought to the Factory. The air was filled with the scent of tauresses in heat, and one could hear the males whining as they were brought out of their stalls to do their duties of the day. Beau checked the two new fillies and felt the creamy substance forming slowly on their labia:

"Good, good! This is a very important task here in our farm, producing cream on your pussies," she said to them. The girls were gasping as their swollen lips opened and closed, yearning a cock that never materialized.

Sean had decided to ride Matombo that day. He got him saddled and walked with him to the Cream Factory. The centaur was instantly aroused by the scent of so many females in heat. He pranced, but Sean gave a hearty kick to his flanks and pulled his reins strongly, making his neck arch back

"Not now, my friend! They are busy giving out their cream; you have to wait until one of them is in her natural period!"

Matombo felt the tug on the reins and stopped prancing. His childish mind registered the man's words; in the past few months, he had grown accustomed to obey his master. He felt as Sean's hand touched his bare skull and went down to his nose ring. He frowned as the man gave the ring a gentle pull; his voice was addressing him:

"You are a very good centaur, Matombo. You have learned to serve well, and I am proud of you. Now, let's gallop!"

Sean kicked his heels on the huge taur's ribs and let him go. Matombo had become an excellent mount, swift and agile, responding well to commands from the reins. He was happy in the farm; he had a nice place to sleep, had females almost every week to fuck, and ate well, much better than in the woods. It was true that the humans wanted him and the other males to do what they called work, and that was not always fun; but all in all, he thought, he was better off than before. He sped up as his master swatted his rump with the riding crop, and jumped easily a fence, his hooves touching lightly the grass as he ran with the man on his top.

Sean was pleased. He could feel the wind on his face, and the sensation of having that powerful black animal under his orders was exhilarating. Matombo had given him seven foals and in the next few days would cover some more mares. He could be easily sold for thirty thousand dollars, but Sean was not intending to dispose of him. His seed was precious, and when drained he gave easily the requested amount. Sean thought of racing him against Congo, the male he had sold to Francisco months ago. He sniffed the musk of his centaur's sweat, which was covering his torso and drenching his collar.

He was not sexually attracted to Matombo; what pleased him was the sheer power to make him obey, a sensation that could make his cock swell under his trousers. He directed the centaur to the lake and dismounted to give him some rest.

Then he heard his phone cell ringing. It was Linda:

"Are you riding Matombo?"

"Yes, why?"

"He is being requested at the mating stall. Missanga is to be mated to him and she had just come into her period. Could you bring him back?"

"Sure, I will be there in ten minutes."

He motioned to the centaur:

"Work for you, my friend... There is a mare in heat and Miss Linda says that it is you who have to cover her."

Matombo's eyes gleamed with lust. He let himself be mounted and carried his master back to the stalls. He was led to the mating stall, where Missanga was waiting for him in the mating device, her legs spread out and attached to the metal bars. In the next device, Moleke was covering another mare.

Matombo put his legs over the mare's rump and entered her without warning. His long cock was stretched out; he bit Missanga's neck and ears to make her stay still, and felt the delicious pussy of the girl closing on his cock. He shot quickly into her, but kept fucking her hard, taking advantage of her being held by the straps on her back legs. Missanga wanted him out, and tried to free herself from his grip; Sean swatted her rump with the crop:

"Quiet, girl... we want Matombo to make a fine foal in your womb..."

He pressed the touches on his phone and called Linda. He wanted her to oversee the mating, partly because she was good at that, and partly because he wanted to watch her reaction to the scene, as Beau's cream had been rubbed on her pussy.

As she arrived to the pen, Linda's face showed all her anguish at being unable to touch herself. Sean smiled:

"You are horny as hell, aren't you... Come here!" He shook the key to her belt in front of her eyes and watched amused as her eyes followed his movements.

"Kneel down, I need some licking here..."

The girl's eyes went wide with surprise.

"But Sean! How can I...?"

Sean was opening his trousers and pulling out his cock.

"Come here... You did it well yesterday; I want it done again. Or it will be a week instead of a day... You decide."

Linda had no choice. She knelt before Sean and took his cock in her hands. Her lips pressed on it and she began to lick the man's cock. Her clit was swollen and she could not help moving her hips and thighs, in the hope of getting some relief. It was not possible, and she knew it, but instinct spoke louder.

She gave Sean a marvelous mouth job. Her tongue flickered around the cock, licking quickly the tip and going back to the base; she played with his balls; Sean's hands were holding her head in place, his fingers running on her soft, brown hair. Her tongue was velvet and silk; he rocked his hips in pleasure, preparing to shoot in her mouth. Then he came, in quick, strong thrusts, his juice spurting out in jets into the girl's mouth.

He did not want to humiliate her too far, so he let her spit the sperm on the ground. She took some tissue from her pocket and cleaned him.

"Let us go to the other stall," he said. She followed him. "Now take your pants out, I will give you some relief."

Linda did it as quickly as she could. Sean unlocked her; he had an idea and smiled at it.

"Go into the mating stall and hold the front bar. I will take you centaur fashion today."

Linda hesitated; the man waited calmly, sensing the battle in her mind. Finally, she lowered her eyes and went obediently into the metal rectangle. Sean took her ankles and strapped them to the metal vertical bars; her ass was now exposed, as she had to bend her torso to hold the bar with her hands. Sean took a deep breath and entered her pussy in a rapid thrust.

Linda felt the cock coming into her and sent out a loud sigh. Her lips were swollen because of the effect of Beau's cream, and besides she was badly in need, not having been touched for so many hours. She had a rapid first orgasm, contracting her belly and shaking her thighs in the spasms of pleasure. On his side, Sean was feeling all the pleasure that her wet, tight cunt could give him; the girl squeezed his cock like a hungry lioness, her delicious ass moving up and down as she tried to pull it into her womb. He let her work on his cock, licking her neck, biting her ear and cupping her turgid breasts in his hands. The tension mounted quickly in his cock, and he came again, unloading into her what he had left in his balls.

As he went out of her, he considered letting her in the mating device and calling James to have her, but he decided not to. He fitted the belt again on her before taking her ankles out of the straps and letting her dress up.

"OK, Linda... Now you have had some pleasure. Next period will be three days in a row, with openings only to receive more of Beau's cream." The girl's eyes opened wide as she heard those words. Three days!

24. The ebony volunteers

They were three nightmarish days. The pressure on her clit mounted and mounted, as the effect of Beau's secretion worked in her entrails. Linda could not sleep more that two or three hours in a row; she kept twisting her body on her bed, shaking her legs wildly in a vain effort to get some relief. She took to doing physical exercises to cool off the tension; she did push-ups, abdominals, everything that she could remember, until she got exhausted.

Sean did not yield to her pleas. He wanted her to go all the seventy-two hours; he was mentally savoring the sensation of penetrating her after that time. On the afternoon of the third day, as he was riding Kumbo to exercise him, he saw Linda jogging around the inner part of the farm fence. He stopped Kumbo and watched amused as the girl climbed on a tree, came back and climbed it again, doing anything to spend off the accumulated tension in her body.

That night, after having measured Linda and seen that the apparatus could barely hold so much lip and clit tension, Sean fucked her for two hours, in every position he could imagine. She was docile as he had never seen her, letting him do whatever he pleased, determined to take the maximum she could from the caresses on her pussy.