Emily, Mary and Ellie sat in front of the rotating hologram, the light reflecting in their eyes as if looking at Christmas lights. They were looking at a glowing model of Emily positioned upside down in a metal bondage rack, her legs splayed open and bent back at the knee. Her arms were bound behind her, arching her back and pressing her breasts forwards.
The doctor spoke: "In this position, we will have optimal access to Emily's testicles." She rotated the image horizontally so Emily's holographic behind was pointed straight at them. The girls noticed Emily's sack was perched directly on top of her upside-down position, the region was highlighted.
"In this exercise we will be measuring Emily's semen generation as a function of testicle stimulation. The plug will also be used to record prostate activity. During this session, no stimulation of the penis or vagina will be necessary."
Mary and Ellie nodded, observing the image closely.
"Good, Mary and Ellie please select the toys you would like to use in this exercise from the cabinet behind me. Emily, please follow me and I will help you into your bondage."
Emily stood and followed the doctor out into the hall, she heard the Kim sisters giggle behind her as the cabinet was opened. As Emily walked down the hall, a million questions raced through her mind but she couldn't formulate her thoughts to get anything out. Before she could, she was distracted by an open door as they walked past. Looking inside Emily saw Maria and Kiah inside, kneeling and facing the wall opposite the door. Their gym clothes discarded, she saw they had on only slim lingerie sets. As Emily tried to get a closer look, she saw what they were doing. Kiah's head bobbed furiously as the head of the dildo was treated to a vigorous assault. Maria's head began to shake until she popped her mouth off of the dildo, coughing. She had pulled three-quarters of the length out of her throat, strands of saliva dripping off the glistening tip.
Dr. Lee reached back and grabbed Emily's wrist as she pulled her through the door at the end of the hallway. In the center of the room before her stood an intimidating rack of metal, padding and straps. She knew what this was for. Around the room various monitors and control panels beeped to life.
"Welcome to our primary research facility" The doctor spoke. "Please, wait while I program the proper shape to our bondage rack." She began working on a control panel.
Emily wandered up to the rack in the center of the room, mouth ajar. Looking around, she asked the doctor nervously.
"Doctor.. what if this is all too much for me. I never imagined this when you first described your research."
"Honey, I know we have a contract but I want you to know you are free to leave at any point. I don't want you to feel forced into any of this. Consider your debt taken care of just through your participation so far.
However," She continued. "You can't pretend to tell me you aren't curious. I can see it from your body. Not to mention I saw you observing our special plug. If you decide to stay, I can promise you that you'll be taken to places most people could only dream of. I just ask that you trust the process. Trust my researches, and trust me."
Emily looked at the doctor, she could see the same genuine care that she had originally seen when she agreed to this project.
"I know.. I'll do my best" She said.
"I believe in you. We all do. You can see the girls' excitement." The doctor paused before continuing. "Please, remove your clothing and step under the rack, the program is ready."
The servos in the rack whirred to life as they repositioned themselves to support the position from the hologram, which was now spinning around on a projector in the corner of the room. Emily removed her clothing, stepping forward.
As the doctor helped Emily into her restraints, she was amazed at the comfort of her bondage. She was supported in every way necessary, although she was entirely restrained in the manner described in the briefing room. Her testicles perched squarely above her upside down body, a silicone ring was pulled over them. Her smooth sac was stretched gently over her balls.
At that moment, Mary and Ellie walked in and began placing objects on the counter in front of Emily's rack. From this angle, Emily couldn't see what they had selected.
"Good, you're here. The exercise can begin. We are scheduled for thirty minutes of testicular stimulation but we aren't time constrained." The doctor used the control panel and Emily felt herself being lowered until her nether regions were right at chest height of the girls around her. Looking up between her legs, she saw the excited faces of Ellie and Mary. She also saw her delicate meat, hanging down towards her face.
"I will now insert the plug to monitor seminal generation" Dr. Kim reached out and picked up the black plug, covering it in a thick layer of gel lubricant. Using her finger, she applied some to Emily's butthole which was prominently on display in her exposed position. The small plug slid easily in with the aid of the lubricating gel. Emily inhaled sharply, anticipating the plugs movement. She felt plug slowly expand inwards, curving up to meet the region she now knew contained her prostate organ. Her eyes widened as the probe made light contact, she felt as if she was being prodded in her very core. Almost as if the base of her cock was being caressed from inside her. The plug backed off.
"Baseline readings of semen levels are collected. Current levels are small but nonzero. Interestingly they are higher than they should be, considering your last collection was only yesterday. It seems you have higher than average semen production even under no stimulation."
"Mary, Ellie" She continued, "we are ready. Please begin."
They smiled at each other before looking back down at Emily, her wide brown eyes staring back up at them.
"Don't worry Emily, we have everything under control" Ellie spoke. Looking back up at Mary she continued "Look at this perfect set of balls. Look how smooth her pink little sac is, don't you think we should get it nice and slippery before we continue?'"
"I agree wholeheartedly." Mary replied. "But I don't think any more of that gel is going to be necessary." She stuck out her tongue to a point, expertly tracing circles and figure eights in the air.
Positioning herself directly in between Emily's splayed knees, she leaned in, the girl's exposed sac presented at the perfect height. Looking up, Emily's vision of what was happening was blocked by the girls standing around her. Suddenly, she gasped as she felt the warm tip of the flute player's tongue make contact with her left nut. The light tickle provided by the barest contact of her tongue was swirled around the surface, tracing out shapes of all kinds as the skin was slowly covered in saliva. Due to the small contact surface, it took several minutes until Mary was satisfied with the coverage on this side, before moving her attention over to the other testicle. Giving this side the same care and attention took an additional several minutes.
Emily, lost in the sensations suddenly jumped in her restraints as she felt the plug prod her again.
"Semen production increased 5%." The doctor reported from out of sight.
"Make room!" Ellie exclaimed as she pressed her way next to Mary between Emily's knees.
Mary straightened up and nodded at Emily's glistening sac, now covered sufficiently in saliva. Ellie reached aside to grab a set of gloves off of the table next to her. After placing it on, she reached her hand down to give Emily a close look. Emily could see that the tips of each finger had lightly feathered tips.
She reached back up and tapped Mary on the shoulder, who moved out of the way. Ellie positioned her hands on either side of the shiny sac, now slightly pink from their treatment so far. Ellie reached out with her pointer finger and dragged one of the feathered tips directly across the center line of Emily's scrotum, eliciting a startled jump from their constrained captive.
Emily started at the new feeling of the feathers across her teased sac. The feeling was so light yet so focused. It was so intense, her body wasn't quite sure how to respond. Not that she had many options, in this restraint all she could do was try to endure the onslaught of sensations.
Ellie continued lazily dragging the feathered tip of her pointer finger across the smooth skin of Emily's scrotum, as she squirmed in her bondage below. Adding in the pointer finger from her other hand, she drew light circles around each nut.
"10% increase, great work girls!" Dr. Lee called out.
Ellie smiled at the news, replying back. "It's so much fun teasing this poor exposed set of balls. You really gave us a great position to work in professor!" A devilish grin crept on to her face. "I have full access to her exposed gonads, I'm going to play these things like Claire de Lune
With that she suddenly dragged all ten of her feathered fingertips across the taut skin, caressing each nut in a flurry of coordinated movements. Emily shrieked as the assault on her testicles continued, unable to move her sensitive balls away from Ellie's practiced motions. She jerked and writhed in her restraints, but the straps held her steadfastly in place, her tortured ballsack still perched perfectly on top to be teased by the skilled piano player.
Ellie continued, varying the pace of her attack as the minutes ticked onwards. She angled her hands to properly tickle the stretched skin from every angle, rotating her wrists around the plump sac as she continued. Emily continued to squirm as she desperately tried to escape the fingertips.
