omg - because he stands to lose you. Once he has you again, he backs away until the next stroppy/hysterical outburst. Mine was exactly the same.
He can only let you down if you give him the opportunity to, my love. No contact = no opportunity for him to let you down whatsoever.
Re being friends, my BR NC mailout has this to say about trying to stay friends:
"If you want to be his friend in spite of the fact that 1) you were never friends in the first place and/or 2) he treated you poorly in the relationship, I have to ask,
Why the hell do you want to be friends with this person?
If you want, need, or expect anything from your ex that you're cutting contact with, even if you don't express or acknowledge it, you have ulterior motives for wanting to be their friend
If you are no longer emotionally attached and have gotten over them and moved on, let's say 6 months to a year down the line, go ahead and knock yourself out. That is of course if they actually have qualities that make them worthy of actually being your friend.
If someone is good enough to be your friend, how has it got to the point that you need to cut contact?
Bearing in mind that you have cut contact, what makes you feel that they will be respectful of your boundaries when you become their friend?"
I'm still processing this info myself. It's starting to work it's way into my head, though :( Slowly.