Originally Posted by folikeln
M stepped up and tried to be my everything. We didn't think A would change his mind (as much as I wished he would) so we tried to comfort each other with words of exclusivity. That M and I would learn to be happy with just each other and without A. It worked for M but never really seemed to work for me.
You need to be honest with M about that. I can understand wanting to say what someone wants to hear as a way to offer comfort, but it was unfair to lead him to expect that you want monogamy. Whether you choose to be with A again or want the option with others, should someone else come along, M needs to know your stance and be able to make an informed decision about whether or not he wants to be in it with you practicing polyamory. He could still be mono with you while you are poly, too. Just because you may want to be with A again, doesn't mean M has to also.
But I wonder how much A really is willing to be in it, either. It doesn't make much sense to choose between them if he doesn't have a good, solid proposal of whatever kind of relationship he is offering you. If he's all vague and non-committal, tell him to come back and talk to you when he truly knows what he wants -- because it's not right to throw you into a tailspin over something uncertain!
I see lots of talking in your near future if you want things to work out!