Show her who is in charge

You stand to look at her more closely. You're not particularly tall, but she is so short even in heels that you tower over her. She looks up at you, self conscious and nervous. You stroke her hair, then let your hands run down her body, fondling her tits and rubbing the nipples.

"Sir!" she gasps, half shocked, half giggling. She almost pulls away, but thinks better of it. As you rub her breasts she arches he neck and looks up at you, a half smile on her face.

"Have I been punished enough, sir?" she grins. She's getting cocky.

"The spanking is over, for today at least, but I'm not done disciplining you yet."

"What do you mean, sir? What are you going to do?" You slide your fingers down her belly caressing her silken flesh. You reach the fine fur of her pubic patch, stroke it, and continue, your fingers sliding between her swollen cunt lips. She gasps sharply and tries to pull away, but he hold her with one arm while your other hand explores. You look into her eyes, making your face stern and cold. You can see the playfulness which had started to return to her disappear.

"I'm going to fuck you. I'm going to put you on my desk and fuck you."

Her eyes widen in what might be panic. "You can't sir, oh please you can't."

"I can and I will."

"But I'm not on birth control, and, and, and I'm worried that your thing, well it's so big Sir. And I'm so little. It would hurt me, Sir." She looks genuinely panicked now and her helplessness excites you. You pull her towards you, pressing her tits against you while your hand probes her cunt. Your cock, which you never put away, rubs against her.

"Please sir, I'm really not on birth control. I'm not. Please sir. Please? I'll suck you instead. I promise. Please don't, don't.... don't .... fuck me," she begs, having trouble getting the word out. She starts to slide to her knees, obviously trying to keep her promise.