Chastity Cage Tease

My sub's cock is locked in steel, but I'm in a playful mood. I blindfold him and restrain him, legs spread, then take a small paintbrush and delicately tickle his caged cock through the bars. He immediately bulges in his cage, desperate for more. I also break out a mini magic wand vibrator and press it against the cage for some tingling stimulation. I get him right to the edge - he's shaking - but of course I don't let him cum. He's left throbbing, denied, and drooling pre-cum in that little cage.