It seems as if you may have hit upon something: the supervisor position, his friends and their freedoms and he has "none" (what he and many men don't realize is the great, awesome gift of marriage and children and there's great FREEDOM in that!)
One thing that I would encourage you not to do as HARD as it is and BELIEVE ME I KNOW IT IS HARD but, just try it out a couple of times and I believe that after you train yourself to do it, you will feel so much less stress yourself AND HE will be singing a different tune. Ok, brace yourself . . . here it is: don't argue back with him. Bite your tongue. Be agreeable. If he says "you just watch. You'll be begging me to come back." Say, "Yes. I understand you feel that way." I know it sounds corny but, this does a couple of things. Firstly, it puts you in total control of everything-- you've disarmed him completely. You've agreed with him which is the last thing he expected AND wanted. But, what does he say from there? "Yeah you will!" Well duhh, you've already said "yes, I understand you feel that way." Then he'll move on to the next thing, to which you will reply "yes, I understand you feel that way." He will be totally floored and he won't know what to say or think. Pretty soon he will see that he is not getting under your skin (ok, maybe he still will be getting under your skin but HE'LL NEVER know with those responses!) He will start coming around and pursuing you. I truly, truly, truly believe this will work. I've used this method before and it worked like a charm. It disarmed him and got us into an environment where we could actually talk about things. Did we talk about things immediately? No. But after hours of conversation, about a week later he was putty in my hands. HA!
It sounds bizarro and against everything our fight or flight instincts tell us. But, traditional methods aren't working, right? Try something else... you might be pleasantly surprised!
Also, there's a book called "The Dance of Anger: A Woman's Guide to Changing the Patterns of Intimate Relationships" by Harriet Lerner and I highly recommend it. When I was in in-patient alcohol/drug rehab, my group therapist gave me a copy of it. Very insightful.
Warmly,
Brandi