The Two Sisters Pt. 01

Then Simone unstrapped Birgit and led her into another treatment room.

Chapter 15: Preparations

Birgit was super excited to see what was going on with her sister When she entered the room she had a strong premonition that all was not well. An alarming looking gyno-chair captured her view. The gynecological chair her sister was strapped on yesterday had already made a pretty menacing impression, but this one beat everything. Birgit gulped as she imagined that Anita would soon be strapped down on this torture rack.

Next to this chair stood some supply carts with accessories, but these were covered by cloths. When she looked around the room, her presentiment was further enhanced because there was a different chair than was set up before for her. Although this one was also upholstered with white leather, it was designed much more robust and bonds were attached everywhere. Aha, so this time I will be also strapped down totally, Birgit thought; a shudder ran through her body. Please sit down Simone said, and fixed Birgit to her chair. The Foley catheter was connected to a drain provided in the seat. Birgit couldn't move a millimeter anymore thanks to the many shackles.

Simone explained that Anita's upcoming treatment would be quite strenuous for her sister. Because she had to concentrate at times, she must not be distracted or disturbed in any way. Then Simone also put a ball gag with a built-in drinking device in Birgit's mouth. Birgit was feeling really queasy. What the heck will go on here?

Simone left the room, presumably to pick up Anita as Birgit suspected. Birgit looked around the room, observing in particular the gyno-chair; or more operating table. Like the other treatment chairs, it was mounted on a thick, height-adjustable column, but at that point the similarities came to an end.

The body support consisted of several individual segments, interconnected in hinges. These segments consisted of a stainless steel ground plate upholstered with latex padding and they were shaped according to the outline of a human body. There were separate supports for feet, legs, arms and torso; even for the head, another separate plate was provided. The supports for legs and arms were two-parted and were, like all segments, individually adjustable. At the end of the armrests two vertical handles were attached. Additional numerous heavy-duty straps commanded respect. The surface of the latex upholstery were not flat, but rather formed out to match the shape of the human body, so that Anita would lie down in a kind of hollow mold. The adjustment of the individual segments was electric; Birgit could see from a control panel standing next to the chair. Apparently the strapped patient could be moved into every position imaginable.

The door opened and Simone and her colleague led Anita inside. Anita's sight caught Birgit's eyes, because her body glistened with oil from the previous massage. Birgit thought she looked extremely sexy. She looked at her big sister and she got aware of how pretty Anita was. Her small, firm breasts stood out perfect from her toned body, her nipples were stiff with excitement, her long brunette hair was now braided into a ponytail. Her petite, slender body really was a very erotic sight. Anita had already brought herself into a trance-like state, because she did not notice her sister at all. She looked at the gyno-chair on which she would soon be strapped to, closed her eyes for a moment and took a deep breath. Then without hesitation she went to the chair. Simone's colleague drove the body support down so that Anita could easily sit down on it. Then the chair went back upwards and the assistants began to fasten the straps. Simone fetched two oddly shaped parts with which she fixed Anita's feet. Birgit thought they looked similar to water-ski bindings . Simone put these devices over Anita's feet and inserted them into guides at the vertical footrests. These latex bindings were slightly conical and as Simone slid them down the guides, she clamped Anita's feet to the footrests. Then she fixed these bindings in the guides. Meanwhile, her colleague had already strapped Anita's arms. Her head laid in the hollow of the headrest and was now tightly fixed with a kind of harness that went around her head in multiple planes. A wide latex belt was tightened over Anita's chest. It had openings for her breasts, which jutted out provocative. Her legs and her pelvis were also buckled with many straps to the body supports. Anita could hardly move. Then, Simone spread Anita's legs, put an Foley catheter in her bladder and led the tube backwards over Anita's abdominal wall to the side and connected it to a fitting below the torso support.

Simone then drove Anita's legs wide apart and simultaneously towards her body. Her sweet little butt was now easily accessible.

Just as Simone began to lubricate Anita's slightly gaping anus, the door opened again and Dr. Lay appeared.

Just like yesterday, she had dressed again in black latex. Today she wore a black latex dress that was tight as a corset with a low neckline and that emphasized her large, full breasts beautifully. The dress was cut wide downwards and reached up to her knees. She also wore black latex stockings and gloves. She wore black high-heeled boots. Her blond hair was tied back as severely as yesterday. Dr. Lay completed her ensemble with strong makeup. In whole, she made a redoubtable impress on Birgit.

She went over to Anita and greeted her briefly. Hi Anita, I hope you're ready for your anal stretching? Today's its getting quite hard as you already know, she said with a stern face. Yes, said Anita, I am now relaxed and opened up. This may help you a bit, Dr. Lay said with a menacing undertone. Then we'll begin. First, I'm going to drive you into the correct position.

She Dr. Lay pressed a few buttons on the control panel and the chair, together with the defenseless Anita, began to move. She initially tilted Anita slightly back so that she was horizontal. Then she turned her thighs even further towards the body until they aligned with Anita's torso; the lower legs moving in sync. Then she spread her legs apart a bit and the legs turned at the same time further out. The movements of the chair ingeniously imitated the natural movements of the body. Then her arms were bent and went down behind her back. The strenous position caused Anita's breasts to look even better. Anita sighed a little, because a proper tension had built up in her body and she was pressed firmly into the shackles. She could now no longer move even a single millimeter.

Birgit watched spellbound. The perfectly shaved pubic area of her sister was now completely accessible and her cute asshole was squeezed out provocatively. The extreme spread of her legs had pulled her buttocks apart so far that her ass was a virtually flat surface with her slightly open anus in the center.

Dr. Lay now had free access to Anita's pleasure hole. She took some lube and massaged Anita's rosette. So she said smiling profoundly to Anita, let's see how far you can open your small hole today.

Birgit swallowed. Anita had been extremely opened up just a short time ago; Simone had even anally fisted her! And now it will start boi time?

What the hell would Dr. Lay have her sister endure now? Birgit realized why she had been bound and gagged. Her excitement ceased when she thought of what lay before Anita. Slowly, she felt queasy again.

Dr. Lay took a three prong anal speculum and inserted it into Anita's already slightly gaping anus. Due to the extreme position she had lost control over her sphincter and could not quite close it; which was what was actually intended. Dr. Lay turned the screw, slowly and evenly the speculum opened. When she had reached approximately 6cm in diameter Anita breathed hard in and out, but Dr. Lay turned the screw further. Then Anita moaned loudly and Dr. Lay said, well, I don't think you're not relaxed enough. I should give you a helping hand, though. Please fetch the penetrator, she said to Simone's colleague.

Penetrator? That will probably mean fucking machine, Birgit thought as the assistant rolled the unit in from the supply room.

On a white painted frame was indeed mounted a kind of fucking machine. Birgit had seen such a device in an erotic catalogue, but this one was built much more stable.

At the front was a mandrel sticking out, on which a dildo could be attached. This mandrel was connected with a pivot to a flywheel, which was powered by a sturdy looking motor.

Mounted on its side was a control panel. The cable that was hanging out got connected to the main control panel. The assistant positioned the machine centered in front of Anita's butt. Simone screwed a thin dildo on the mandrel and rolled the device closer towards Anita. Dr. Lay regulated the height of the chair to align the dildo with Anita's asshole and locked the frame at its wheels. The assistant turned a threaded spindle and adjusted the machines angle to Anita's position. Simone drove the dildo slowly into Anita and verified the position of the machine.

Just a small readjustment of the angle and the unit was ready. Simone drove the dildo back out completely out of Anita and changed it with a much thicker specimen. Birgit estimated approximately 6cm in diameter. The dildo was thickly coated with lubricant and then pressed forward slowly, deep into Anita's compliant backside.

Anita, who had not muttered a single peep until now, groaned full of enjoyment. Her pussy was a little damp, as Birgit noticed after a sharp look. It was still hard for her to understand that her sister really enjoyed this seemingly extreme treatment. But no doubt, beside the strain, that there was lust at work in Anita. Birgit realized that the anal masochism of her sister still felt strange to her, even if she had received a very good explanation by Simone yesterday. She respected her sister, and somehow Birgit admired Anita very much, but she realized that she could not share such extreme feelings. Simone adjusted the turning points of the dildo and Dr. Lay picked up the controller. So now you're going to get a proper fuck, she said to Anita, so that your ass will be able to stretch out very far afterwards. She turned on the engine and the dildo began to fuck Anita's butt. MMMMHHHHMMM Anita said as she felt the movements of the thick prick in her hot ass. With gradually increases, Dr. Lay regulated the speed until the dildo made about 2 strokes per second.

That was quite decent, Birgit thought.

, Dr. Lay said. Thus, she left the room. Anita moaned softly. She seemed to really enjoy the fucking machine. 15 minutes later, Dr. Lay was back and drove the dildo out of Anita's butt. Simone gave her a much thicker one, which was screwed onto the mandrel and soon disappeared in Anita's small yet eager ass. Anita had to endure the fuck for another 15 minutes, then Dr. Lay said that it would now be time to take a real dick. Birgit's eyes widened when Simone was preparing the next prick. This dildo was easily seven centimeters in diameter!

Birgit was amazed. Now it's getting down to business, she thought. Although the dildo had a smooth shank like its predecessors, this time a real big penis was formed. Simone mounted it on the mandrel and Dr. Lay drove it right up into Anita's anus. She probably felt how thick the dildo was that now entered her, because she was breathing audibly. Dr. Lay slowly drove the mandrel forward. Anita moaned as the tool stretched her taunt sphincter. Dr. Lay did not stop and let it continue to drive into Anita. Oooohhhhhcchh came softly out of Anita's mouth.

Well, you will probably feel this one better, said Dr. Lay. Yes, he's really nice and thick, Anita moaned excited. Then you may enjoy it a while said Dr. Lay. I'm going to penetrate you with various settings she said, then you should be pretty relaxed so I'll have no trouble during your expansion. I have still some plans with you for today.

, and something like a horny anticipation crept up her back. She got really excited at the thought, because now she had accepted the fact that her sister got real pleasure by this sadistic treatment.

Anita got close to a orgasm several times as she was fucked this massive dildo. Birgit was also kept pretty hot at the sight of her sister strapped down on this obscene rack and getting fucked mercilessly by an emotionless machine. Birgit wanted to play with her clit, as she imagined that it was she who knelt in front of a nice guy and was fucked her ass heavily. Hopefully I will have a new boyfriend pretty soon, she thought. He won't know what hit him, she chuckled to herself.

Dr. Lay fucked Anita rather quickly and seemed to be very pleased. Birgit noticed that when she was close to cumming, every time Dr. Lay would regulate the speed down and Anita's lust waves faltered. Then Dr. Lay would change the settings of the machine and the stiff dildo would drive in long lines completely out of Anita's ass before it entered again. Every time the fat acorn of the phalic dildo stretched her sphincter, Birgit could clearly see how Anita's anus was pulled out before it gave up and let the dildo slide out.

Dr. Lay increased the speed more and more. Anita was moaning now. No longer purely pleasurable, she seemed to reach again that desired state in which pleasure and pain were balanced. Dr. Lay repeatedly changed the speed between very slow in and out and brutal penetration. Anita seemed to be really torn between all extremes of her emotions. At times she moaned softly, then she gripped the handles and yelled out in excitement.

Dr. Lay played masterfully with her feelings. Finally she changed the setting again so that only the fat acorn penetrated Anita's sphincter in very short strokes. She increased the speed up to about 2 strokes per second, leaving Anita alone again for a quarter of an hour. From time to time Simone dripped lube onto the dildo, while Anita now showed clear signs of discomfort. Apparently this quick penetration of her sphincter only was not so easy to bear. Birgit still looked spellbound. Really amazing what's going up here, she thought. She never would have guessed what was hidden inside Anita.

Dr. Lay came back and stopped the penetration. This "relaxation exercises" of her sister had lasted about two hours.

Then let's see if your little asshole can now widen better, said Dr. Lay and picked up the large three-prong speculum again. She slowly turned the screw and indeed, Anita opened up much easier now. Just before about 7cm had been reached, Anita moaned softly. Well, now it works so much better, she said to Anita. Now we can begin.

Birgit was curious what was to come next.

Chapter 16: Anita's expansion training

Nurse, please get the first cone expander, Dr. Lay said to Simone's colleague.

The assistant again went into the next room, returned the well-used penetrator to its storage place, and came back out again with a very similar frame . This was, however, built significantly more sturdy and had larger wheels. On top of the wheeled frame an elongated square case was mounted; which obviously had a powerful motor attached to one end. At the other end a thick spindle with a threaded connection on its front came out. Like the fucking machine before, this device was also adjustable in its angle by a threaded spindle. The assistant rolled the frame in, centered in front of Anita, and extended a mounting bracket to the front. On the bracket were two strong, long finger-thick bolts These were fitted in holes below the body support of the gyno-chair. With that done, the cone expander, as Dr. Lay had called the device, was fixed to the chair.

Dr. Lay said that she would drive Anita into the stretching position now and picked up the control panel of the chair. Anita was somewhat more inclined backwards so that her head was now the deepest part of the body. Then Anita's back legs went even further, so that her knees were already below her back. At the same time, the legs spread further apart. Anita moaned quietly because of the tension in her body.

Then her arms were driven a little further down to the rear and her breasts pressed out from their bindings exquisitely. Her head was tilted back so far that Birgit, unfortunately, could not look at her face anymore. Anita could absolutely not move anymore. Only her hands turned slowly back and forth around the handles.

In addition, the frame wheels had now been blocked. To the spindle of the cone expander the assistant mounted a dildo and Dr. Lay operated the device. The motor started and the spindle moved slowly out of the housing. When the dildo was inserted far enough into Anita's anus, Simone adjusted the angle of the spindle, while Dr. Lay adjusted the height of the chair.

The dildo drove slowly out of Anita's anus. Meanwhile, Simone's colleague had already lubed a attachment for the spindle, and Birgit now knew why the device was called cone expander.

A black truncated cone made from silicone of about 18 cm in length was screwed to the spindle. Birgit estimated that the front diameter at the rounded tip of the cone was about 6cm diameter and then gently expanded. About 5 cm before the end of this expander, the cone turned into a straight shaft. Birgit watched spellbound. What for incredible devices are used here, she thought.

Well, then let's get started said Dr. Lay, as she drove the cone expander slowly towards Anita's slightly open anus. To welcome you to your stretching session, I will first open you up with a thinner expander, this one goes from 6 to 7 centimeters in diameter. You should not have any problems with it. Dr. Lay pressed some buttons on the control panel and the expander moved slowly.

Anita moaned lustfully as the tip went into her anus. Evenly, millimeter by millimeter the cone drove into Anita's receptive ass. Without stopping, the powerful motor pressed the cone inside in Birgit's sister until it had finally sunk in up to the full circular diameter. Dr. Lay drove the cone back out rapidly and a new journey in Anita's rectum began. Ten times she repeated this procedure, accompanied by Anita with soothing sounds. Then the expander was driven fully back and Simone unscrewed it from the spindle. Her colleague handed her the next, larger cone.

Dr. Lay said, now comes the next one, from 6.5 to 7.5 cm. To Brigit's astonishment this cone was absorbed by Anita almost without any problem in one stroke. Anita breathed only once heard and deep as the full diameter stretched her ass. How thick the expander looks, when it's in Anita's little butt, Birgit thought. Incredible. During the insertion of the next expander from 7 to 8 cm, some resistance was clearly quite noticeable. It's really huge, Birgit thought gulping as it was screwed to the spindle. This monster is supposed to fit into my sisters small ass? Madness. How can she stand this?

Dr. Lay drove the expander into Anita's anus, and the tip of at least 7 centimeters in diameter pressed her wide open sphincter. Now it's getting a bit harder for you, Dr. Lay said to Anita.

When Anita felt Dr. Lay drive the stretcher into her, she closed her eyes and relaxed. She let her anus relax and await further insertion of the cone. Birgit watched eagerly as the cone's tip spread her sister's ass wide and penetrated through the sphincter slowly. Anita quietly breathed in and out. Millimeter by millimeter, the strong engine drove the cone into her. Anita's sweet asshole became more and more spread open. About a third of this cone expander had disappeared into her, as a soft moan and strong breaths revealed that she had to make some effort to endure this strain. Still a little more of the cone pressed into Anita's ass before she moaned loudly and Dr. Lay stopped the movement. Anita lay panting in her bonds. But the pause that Dr. Lay gave her was short. The motor hummed again and the cone continued its journey into Anita behind. Birgit regretted not being able to watch her sister's face. Surely her stress was to be seen clearly, she assumed.