Mary, slowly and surely pushed the ball into the crevice between Amelia's ass cheeks. The cold metal would have made her jump, if she could have jumped. Her confinement didn't offer that possibility. If she tried to move a foot, she was sure that the foot would leave the floor and her weight would be supported by the other foot and her hair. She didn't want her weight on her neck, but the hair afforded her the ability to "balance" herself since she couldn't move her feet easily.
All the same, the ball's cold touch forced her to cringe. (Later that night, Dave would joke that he actually heard her asshole clench tighter to repel the coming invasion.) But Mary was experienced at this, so she ran the cold metal up and down the space between the two fleshy globes of Amelia's butt. It warmed in that tight space quickly. A new sensation was felt and Amelia realized that her asshole was being lubed. She worked to relax; she didn't know when the insertion was coming but knew that it would take all of her skill to keep from panicking and clenching, and possibly making the insertion difficult or worse, painful.
Mary's soft finger rubbed the lube in a circle around the tight, light pink bud and Amelia calmed her breathing and enjoyed the sensation. He had certainly trained her ass to accept his tongue, his fingers, some toys that they'd purchased, and even his cock, but this was going to be different. She called on everything she'd learned, every experience at being anally penetrated.
So when the woman behind her applied pressure to her most taboo spot, she continued to breathe normally, relaxed, and enjoyed the sensation as her sphincter was stretched, slowly penetrated, and tested for its ability to accept the gleaming ball on the hook. She closed her eyes and her inner voice howled at the intrusion, but her inner sub began to glow. She concentrated on the sensation, on the service she was offering, how it would please him if she could "perform" in front of all these people, how he would tell her how proud he was of her after this was over. She reveled in that thought, got lost in it, and could feel herself luminescing in the dim room. Center of attention, bound more to help her deal with what was happening than to keep her in place (for she would willingly do whatever he asked), and bent over to allow for easier performance of a task, she was floating.
Mary was incredible to her; gentle yet forceful, slow but insistent, and careful not to go too fast or too far. She watched Amelia's body for reactions or signs of stress. The girl was a champ. Mary thought to herself that "this one is well trained." Finally, the hook was past the tight opening and Amelia's crinkled skin squeezed down around the narrower shank of the hook.
