I'm lying, naked, on my back. My legs are strapped up in stirrups and forced uncomfortably wide apart. I'm exposed, vulnerable, helpless. Leather straps secure my wrists, waist and thighs tightly to the chair - I cannot move at all. I can see the metal spout, retainer ring, sounds and lock sitting on the tray, waiting. A small bottle of surgical alcohol and some cotton swabs completes the picture, all but for one thing - the chastity cage. I haven't seen the cage. It's custom made from titanium to my exact measurements - flaccid, of course. It's the one unknown. FItted, it will be inescapable. It will completely enclose my cock, cutting off all access yet leaving me free to wash, move, even swim without any restriction. In fact, there's almost nothing I won't be able to do... almost. Held by the tether alone it will be impossible to escape from, impossible to cheat in and absolutely relentless in it's denial of any and all arousal. She walks in and places the cage on the tray. It shines,a light metallic blue sheen coming from the annodised titanium - my own personal cryptonite. I watch as she sets to work. Given the tether will not be removed for an indefinate period absolute cleaniness is essential. I hear the snap of latex as the gloves go on and suddenly everything is very real. The cold as my foreskin is retracted. The sting of the alcohol on sensitive skin and the pressure of the cotton swabs as it's wiped off. Beads of sweat form on my forehead as adrenaline surges through my veins, uselessly. I feel Her insert the tip of the syringe into my urethra then the cold & the pressure as lubricant is shot deep inside. She slips the first sound in, allowing it to sink deep into me and ensure the lube is fully distributed. I swear She takes a perverse delight in my discomfort as it explores an orifice rarely touched. I'm familiar with the sensations now, I've inserted and removed the spout many times myself but never before has someone else done it. Somehow it's different now that I'm not in charge.. it feels scary. I feel the spout slip slowly into my urethra, then the cold of the sound pressing it further and further down - way down inside where I can't even feel it anymore. Seconds later the sound is withdrawn and I wait for the next violation. I watch Her fiddling with the retainer ring, threading it over the drawstring. A tiny spot of lube at the entrance to my urethra and She's ready. She grips my penis with one hand and flips the ring on it's edge. Deftly She presses it into my urethra, despite the resistance. It stings, the ring is wide and uncomfortable to insert, making me moan a little. She ignores me and presses a little harder. The ring slips part way inside and I know the moment is near. Taking the larger sound She slowly begins to press the retainer ring into me. I try to squirm as it stretches my opening and sends twinges of pain shooting through my cock but I can't. She presses harder and with a pop it goes in. Instantly the pain is gone and I feel only the cold of the sound as she drives it further in. She stops, then backs off the sound very slightly. I feel Her pulling on the drawstring, very slowly. The spout is pulled back up, bumping into the ring. She pulls a little harder and I feel the spout and retainer hit the end of the sound. A gentle tug and it's over - the ring flips sideways and the spout instantly slides through it. She removes the sound and gently pulls the drawstring until the spout protrudes from my cock and won't come out any further... I'm thethered. Deft fingers slide my foreskin back down and I know it's time. Finally, She passes the drawstring through the end of the cage. Using it, She pulls my tethered cock into the cage. I'm shocked at just how tight the cage is. There's no gap at all, it's like a second skin of titanium covering the entire length of my flaccid cock. The spout is pulled through the end and the locking ring secured - a drop of threadlock providing extra security against tampering. She snips the drawstring and stands back, smiling. Meanwhile I gaze at the titanium sheath, already wondering just how long it will be until I see my uncaged cock again....
I'd say it's anticpatory. Once I get the cage and prove it's comfortable, safe and workable I've been told that is exactly how it'll be fitted to me for real.