Eventually she heard the sound of a key turning in the lock and the door swung open. David strode into the room and re-locked the door behind him.
"Assume Position 1!" he commanded and Kristy sank to her knees, wincing as the motion set the weights attached to her nipples swinging.
David bent down and with practised ease flicked the clasp of her bra open. Her breasts were now exposed and unsupported. He removed the gag from Kristy's mouth and slowly unzipped his fly. "You know what to do, slave," was all he said.
Kristy looked up at him. "Please Sir, may I use my hands?" she asked.
David considered for a moment before answering. "Very well, Slave, but the result must be worth my granting your request."
Tentatively Kristy reached out and took his cock in her hand, stroking her fingers up and down its length. Then she brought her tongue into play and allowed her fingers to follow the track it made. Slowly she could feel the shaft start to stiffen and moved her fingers up towards the head where a drop of pre-cum glistened. She caressed it with the palm of her hand, using his pre-cum to lubricate it before encircling the shaft and stroking up and down it's length. As his cock started to stiffen further, she moved one hand underneath to cup his balls, licking each one in turn, sucking it into her mouth before releasing it. David gripped the edge of his desk for support. It looked like she was developing a real talent! She moved her mouth back up his shaft, her hand following in its path, constantly in motion, stroking and caressing, exerting firm but even pressure along its length. When she reached the head she hesitated slightly before plunging downwards and taking him deep into her throat. David gripped the edge of his desk harder. He couldn't let her know how good this felt! Again she pulled back before enveloping him once more. This time she let her teeth graze very lightly against his skin. David could take no more and seizing control he grabbed her hair, powerfully thrusting into her mouth, harder and faster until he came. Without being told, Kristy's tongue swirled around his cock, licking away every last trace of semen and giving him (although she was unaware of this) a chance to regain his composure.
He pulled away from her and readjusted his clothing. "You will lie on the couch on your back, slave" he instructed.
Kristy obediently moved to the couch and lay down on her back, wondering what was to happen next. David took a ball gag out of his desk drawer. "Open your mouth," he instructed and when she complied, he pushed it in and fastened it securely behind her head.
Taking hold of her ankles he pulled her down the couch until her ass was resting high on the arm. He then took the two lengths of cloth he had previously used to gag her and secured her ankles to the legs of the couch. She was now laying completely exposed. David hadn't finished yet, however. He returned to his desk and took out a vibrator.
"You will use this in your pussy and on your clit," he instructed. "I expect you to do your utmost to bring yourself to the brink of climax, although" he warned, "if you cum before I give you permission, you will be sorry!"
Kristy shook her head, wide-eyed. She couldn't do this! To masturbate with someone looking on was something she had never done and she felt her face warm as she blushed in embarrassment.
"Come, come," David taunted. "After your very public display in the hotel suite where you rode, what was his name, Carlos for your own gratification, a little thing like this should be child's play!"
Kristy closed her eyes as she remembered the events that had led to her present predicament. It was true she had selfishly used that man for her own pleasure without considering his needs or feelings.
David's expression hardened. "Do I need to reinforce my instructions?" he asked. "Before she could shake her head he continued. "Maybe I do. Very well, you were warned, slave!"
With that he brought his hand down hard across her exposed clit and pussy, making her scream into her gag. Twice more he repeated his action before pausing.
"Is my slave willing to obey me now?" he demanded.
Kristy frantically nodded her head and took the vibrator he held out to her. At 8" long and almost 2" wide, it was larger than the ones she had used previously and she wasn't sure if she could take it. Nevertheless, she had to try. She switched it on and lightly rubbed it in between her pussy lips. To her surprise it slid between them easily. She was already dripping wet! She moved it up and rubbed it over her clit, groaning against her gag as the engorged nub responded, sending shivers through her body. Finally she gathered her courage and slowly slide the vibrator between her lips and into her pussy. David grew impatient and placing his hand over hers exerted a firm pressure and forced the vibrator deep inside her. Kristy gasped at the feeling of her pussy being stretched. The vibrator was so thick that she could feel her g-spot being stimulated. His hand still on hers, David pulled the vibrator out and once more plunged it in deeply.
"Carry on," he said.
Slowly at first, but then with increasing urgency, Kristy worked the vibrator in and out of her pussy. She instinctively moved her other hand down and started to stroke and tease her clit. David leaned forward and quickly yanked the clamps from both nipples. Kristy screamed against the pain this caused but it quickly merged into the pleasure coursing through her body.
"Don't you dare cum!" David warned.
Frantically, Kristy gathered all her willpower to stave off the impending orgasm. This was a difficult undertaking as David was now pinching and teasing her abused nipples, again causing pain and pleasure to merge. She closed her eyes to better concentrate on the task in hand and so did not see David position himself. The sight of her so close to climax yet desperately trying to hold it back had his cock stiff and engorged once again. He decided to take advantage of the fact that Kristy's ass was so temptingly presented. In one swift motion he pulled out the butt plug and plunged his cock deep inside her back passage. He could feel the vibrations from the device in her pussy start to act on his cock and he knew he would not last long. He started to thrust deep inside her, leaning forward to pinch and tease her nipples. Her breath was now coming in short pants as she struggled to control the demands of her body. Finally he felt he could hold back no longer.
"You may cum, slave" he said giving one final thrust and clamping down hard on her nipples.
Kristy screamed into her gag as she released all mental restrained and her body surged over into orgasm. As she was still shuddering in the aftermath, David released her bonds and gag. He pulled her off the couch and onto her knees in front of him.
"You may thank me for allowing you to cum by cleaning me off," he said.
Kristy dimly recognised this wasn't a suggestion, it was a command! She opened her mouth and took his dripping cock inside, using her tongue to completely lick him clean.