gemzi and i, among many others feel that most things happen for a reason, even though you may never know the reason, and sometimes it slaps you in the face.
everyone involved made choices, as much as they hurt either self or one another. for my $0.03, i say that after not standing up for you, and pushing you back into the friend closet, and having his other girlfriend in your face all the time, that he does not deserve to even be able to tell you how much he misses you.
the conflict now is how do you proceed with your "other options" (ok so i used quotes but may be paraphrasing cause i am too darned lazy to scroll down and find the exact wording.
) it seems very simple. explore the possible relationships and see where they lead. maybe they will one day lead you down the poly path, maybe not. its possible it will be something that gets discussed down the road, or maybe it will be the can left behind on the side of the road.
honestly poly is not for everyone, and sometimes even for those who live it, it is not necessarily for them in every relationship. love at its core, is complex, complete, dynamic, boundless, and limited, in expression, comprehension, belief and execution. i believe from my own observations that the same person can experience compersion (youre right, i do not like that word), and jealousy, based on a specific partner, a lot of times its based on chemical response, that transcends the confines of love, and digs deeper into the primal. so what you have to figure out now, is who you want to build a relationship with, and there are no rules saying that you have to commit to a relationship just because you went on a couple of dates.