Good for you. You're catching on. He'll leave you alone when he gets convinced that he's wasting his time trying to get back in bed with you. That may take a while because he is going to test to see if he can break you down, like he's done in the past. For a while, he may even step up the charm offensive, looking at this as a challenge.

You may be thinking that he'll have to accept that "we can only be friends." You are going to have to accept that you can't even be friends. When he realizes that your "no" is really a no, he is going to be pissed off, mark my words. You kind of "have something" on him, and he is not going to like that one little bit. Be prepared for him to even start talking bad about you at work. He's going to be like a spoiled bratty child who isn't getting his way. Oh, first, he'll go the charm route. But the brat won't be far behind.

I hope I'm wrong, but if he does get nasty, do not even try to sweet-talk him into being decent. You'll just get sucked into more head games, which he is way better at than you are. Be courteous and businesslike. Don't criticize what he's done. You can say something like, "It was exciting getting to know you. You're such an interesting man. But this was not doing either of us any good, and I'm afraid we just can't go on." Say it once, and that's it.

In his mind he may get worried that you are planning on becoming his enemy. So that's why I say don't criticize what he has done. Don't imply that he victimized you. (What you did was consensual.) You can smile pleasantly when you pass him in the hallway. But pass right on by.

Hopefully, you will be able to keep your job. (He may want you out of there.) If you see him getting involved with another woman at work, just mind your own business.

I hope he doesn't get ugly with you, but be prepared for anything. You may have some more lessons to learn from this. Do not let him ensnare you into some kind of "negotiation" with him. Like he'll say "We have to meet over a drink to talk over everything and figure where we go from here." No you don't. Look humble and say, "Try to understand . . it is easier for me this way." You don't want this guy as your enemy. You can even throw some salve at his ego by saying, "I'm heartbroken at letting you go, but I know I must." It sounds like a line from a cheap melodrama. That's okay.

Good luck. I hope this goes smoothly for you. Then keep your dating life private. Don't discuss what you do outside of work at work. Don't give him anymore information about your private life. Don't turn to him for support or friendship. This guy is no girl's friend. When he pesters you consider saying, "What we had was beautiful and I'll always remember it that way." Then get the heck away from him. You'll leave him a bit confused, but less likely to trash talk about you on the job.