He had been rummaging through her vagina with his digits for quite a while now, trying to squeeze more squeals out of his little missus with the way he pinched her clit between his thumb from the outside and his fingers on the inside.
All she could do is helplessly try and muffle her moans, biting her lower lip and hope to whatever deity she followed that he won't get that satisfaction from her yet; after all, she was but a little brat to him.
After having tied her arms together, left hand to right elbow and right to the left, she added a blindfold and kept teasing her, using whatever tools he had in his disposal to milk more and more of her sounds out of her to try and get her to break. His fingers, his lips, his teeth.. and the bundle of toys they had accumulated over the years of their time together.
He waited until she reached her first orgasm, giving her lips a little peck before whispering "Alright, my little lady love. You stay put, I gotta go get something." and simply left her tied up on their sofa which had neatly opened to a makeshift bed when the need arose.
Walking to the kitchen, he put on a latex glove and grabbed the knife he had sterilized prior to placing it in the refrigerator to cool off and get maximum efficacy from what he had intended on doing to his little missus.
Having walked back, quietly as to not give away his position; he ran the blunt part of the cold carbon steel blade against her thighs, her abdomen and her robust breasts. Placing the cold surface of the knife against her neck and gingerly biting at her earlobe to say "You are mine now and forever, so let us not rush that forever part."
Placing the cold, sharp edge against her neck closer to her chin and letting it score her delicate skin just a little bit; letting her now know that it was in fact - a knife without it's knifeguard that was etching at her skin as if trying to cut through frozen butter.
She flinched to start with, but realized that there was nothing she could do in that state as she was bound by him and left to be used by him and in whatever way he had wanted. As the knife lightly grazed the skin of her neck and never had pressure put into it; just the innate sharpness of it alone that could score the first few layers of her skin.
He smiled at her, slowly lowering the knife down and resting it on her ample breast, if not to just pull down on her blindfold and drag it to her neck so she could see what he was doing to her. He picked up the knife and put on it's knifeguard, just to slowly drag it down on it's blunt side yet again and let it touch the surface of which her clit would be hiding.
Grabbing the knife by the blade, he had begun to push the handle into her folds and into her vagina; watching her eyes on occasion to make sure she was staying collected and realizing the gravity of the situation. Having turned the knife to stay horizontally, he pushed the handle into her her - all the way to the cold guard that gave her chills as it was made out of the same material as the blade; if only to just add a counter weight.
"You look cute when you're frightened" He whispered, pressing the cold guard against her folds and watched her eyes before stroking her cheek and holding her face to keep her looking at him. "Your eyes look even cuter now.." He added, leaving the cold steel pressed with his dominant hand and leaning in to tug at her nipples with his teeth and suckle onto her breasts just to bring out more voices and shudders out of her.
After the cold steel had warmed up to her body's temperature, he slowly pulled out the knife's handle out of her vagina and noticed how noticeably wetter she got from having held a knife against her throat, Simply smiling at her and saying "You got wetter than usual, you little minx."
He moved her to lay down on the sofa and folded up the makeshift bed in order to have more space to sit on the ground, undoing her arms's bindings and positioning himself between her legs. His tongue pushed through into her folds and against her slit, just to have a taste of how her fearful juices had tasted; grabbing her outer thighs and spreading her bare butt to expose her holes better for him. Moving his tongue upwards to find her clit, prodding at it with the tip of his tongue and lightly poking at her wet vagina with the index finger of his left hand; just to coat it with her juices and move to poke and prod at her ass-hole. One finger slowly became two fingers, all while his lips had already covered her clit and began to suckle on it wonderfully; the mimicking of a fish face if just to make it better for his little love.
The index and middle finger of his right hand had now slid into her wet vagina, digging inside of her while alternating the motions of his left hand; never letting her feel empty as one hand went in - the other went out. His face buried in her crotch, giving her glances while she was free to play with his hair, tug and push his face down if she so desired.
The alternation of the hand movements had paid off eventually, letting her experience her second orgasm of the night before he had moved to now use her in the way that she was used to - as his little cumdump, his little stress relief toy and his little lady love.