She mind fucks him.

"That's good, Brian. I think you've learned your lesson. I can see from your hard cock that you're very arroused. I'm sure this is the horniest you've ever been in your life. Isn't it?"

If that hadn't been true before, it was now. He could barely nod.

"Well, now that I've let you eat my pussy, of course you're only allowed to masturbate if you follow the rules. Do you remember the rules of jerking off?"

He tried hard to think of them, but shook his head 'no'.

"One, you can only do it when I tell you and where I tell you. Two, you can't cum until I say you can, so you have to stop and hold it any time you think you're close. Three, you have to fantasize about exactly what I tell you to fantasize about. Disobeying these rules will make your dick fall off, but don't worry too much about that, men never have trouble obeying the rules. Following them perfectly gives you an extra big orgasm."

Deborah looked at her watch. There were about two more hours before everyone left for the day. That should be plenty of time to finish her plan. "Now, go over in the corner and jerk until I say we're ready to go home. I want you to imagine that we've been living together for weeks. Fantasize about all the sexy times I've made you service my pussy here or at home. Also, fantasize about all the help I've given you running your business and how hot my superior business skills made you."

As Brian began jerking wildly, Deborah turned her chair to face Brian's computer. "You just keep doing that while I make a few changes to things. After we're done, we'll talk about the new position in the company that you're giving me."