She was beautiful, at least her body was. I couldn't see her face because she wore a black rubber mask. Indeed, the mask was the only thing she was wearing. It had openings for the two nostrils and her mouth but covered her eyes. She was gagged with a red rubber ball that was shoved into her mouth and securely buckled up behind her neck with leather straps. A leash was attached to a D-ring that was screwed into to rubber ball. The leash was secured to a hook in the wall.
She could not move away from the wall because the leach was rather short or remove any of the outfit because her hands were cuffed together behind her back. Hence, she was forced to remain standing because the leash wasn't long enough to allow her to sit down. Not that there was a bench or anything else she could sit on nearby so if the leash would have been long enough, she would have had to sit on the cold concrete floor.
Apart from the bondage paraphernalia she wore she was naked. Her sex was shaved clean. It was a pleasure and very arousing for me to let my eyes trail down from her navel, across her tummy, down over her slightly protruding mons with the beginning of her slit, further down where her sex and slit curved backwards and disappeared between her legs. After taking in the sight my eyes went up to her breasts. They were full yet pert, not too big or too small, but had just the right size for my taste. Gravity made them slightly drop downwards but the nipples, the size of small thimbles, stood out and proudly pointed upwards from the framing areolas.
I looked at her from behind. Her ass was pear shaped and petite. Her legs long and slender. Her waist narrow. She was just very proportionate with no sign of any wrinkles or excessive weight. I couldn't see any hair sticking out from the hood so I couldn't tell her true hair color. Not that it mattered but it would have satisfied my curiosity. Although she was shaven clean I was very familiar with the color of her pubic hair.
I opened my bag with its order-to-measure items and took out the waist band of a carbon fiber chastity belt and wrapped it around her. I adjusted it and made sure there was a snug and firm fit slightly cinching her waist. Once satisfied, I fastened buckles to each of her ankles and put a 1m steel spreader bar between them forcing her legs wide apart. They would secure a good view and free access to her behind when bending her forward.
Next, I took out a soft nylon rope and fastened one end to her handcuffed hands. The other end I ran through a pulley that was hanging from the roof and started to pull on it. This forced her hands and arms upwards behind her back, eventually forcing her to bend forward exposing her naked bare bottom. It was smooth and white with no signs of any whipping or caning. I couldn't resist but administered a few strong slaps across each of ass cheeks. Each stroke made her whimper through the gag and rendered a red hue to her behind.
I got a padded leather clad stool from the other end of the room and sat down on it just behind her. This gave me a great view of her rear, her two ass cheeks separated by the ass crack. Slightly further down, I could see her entire vulva, nicely visible between her legs that were forced apart by the wide spreader bar. This rendered her outer labia to become ever so slightly separated allowing the inner ones, which already were quite blood filled giving them a darker hue, to slightly protrude. I could also discern some moisture that had started to fill up the cracks and crevices of her vulva. My member started to become alive by anticipation but was forced to stay half limb by the coarsely netted metal cage in which it was encased.
I retrieved the chastity belt rectal dildo from the bag and put some lube on it. The dildo comprised three separate parts mounted on a hollow semi-rigid carbon fiber composite rod the shape of an L. The tip of the long leg of the L was made up of an inflatable elongated rubber ball, 4 cm long and with a diameter of about 2 cm - which of course would expand when inflated. The middle part was made up of a heavy egg-shaped steel ball covered in a thin layer of rubber and was some 6 cm long but wider with a 4 cm diameter at its widest part. The weight of it would make it shift significantly during movement constantly reminding the person wearing it of something present in the its rectum. The bottom piece was a 2 cm wide and 5 cm long steel cylinder. It did on purpose not have the typical butt plug wedge shape which would allow the sphincter to basically contract as if there was nothing inserted in the rectum once put in place. Indeed, the bottom cylindrical piece kept the sphincter stretched open even when the dildo was inserted all the way to its base. This served the very same purpose as the steel ball, namely rendering the wearer a sensation of that there was a foreign object inserted in the rectum.
The corner of the L featured a valve through which air could be passed to inflate or deflate the rubber ball. This could be done manually or through a remotely controlled pump welded into the shorter leg of the dildo. The corner also featured a click and lock mechanism by which the piece could be extended forward across the vulva all the way to the clit over the mons crossing the tummy until it could be attached to the front end of the chastity waist band.
This shorter leg which would rest between the two ass cheeks gradually changed into a flexible carbon fiber string with a lock mechanism by which it could be attached to the back of the chastity belt waist band.
I put on a latex glove on my right hand and took some more lube and began to massage her asshole slowly relaxing her sphincter. I knew she hadn't had any solid food for several days but was given enough nutrients to drink. She had also been given three enemas over the last few days to effectively empty her.
I gently pushed one finger into her ass, then two, and eventually three. I fucked her slowly with three fingers allowing them to slide deeper and deeper into her until she took the full length of them. When her hole was sufficiently stretched open to accommodate the dildo, I took off the latex glove and put the rubber ball tip against her anus and applied a gentle pushing force. I moved the tip in and out, each time allowing it to go a little deeper.
My efforts were accompanied by her rhythmic moaning. We started to work in sync, for each push I made she thanked me by a loud moan while at the same time relaxing her sphincter even more. Once she was open enough to allow the steel ball to enter, things became easier. I slowly slid the dildo further into her until the egg-shaped ball kind of sucked itself into her ass and fully disappeared into her, allowing her sphincter to close around the cylindrical piece. I pushed the dildo deeper into her until the bottom of the dildo rested firmly against her ass crack.
I heard her panting with pleasure now that she had the full 15 cm length plugged into her rectum. I secured it by attaching the lock mechanism to the chastity belt at the back. This would do and hold the dildo in place until I had installed the vaginal dildo and extended the chastity belt crotch-shield to the front.