Thank you for the responses.
I did manage to have quite a long drawn out conversation with him and we are on a bit more solid ground right now. I did make a point to tell him that its unfair for him to now decide to change our agreements because he is scared or uncomfortable. He is still interested in pursuing this lifestyle change and for me this is a positive step. He isnt sure about this particular person anymore, and its so hard for me to not involve myself. In one of our discussions about it we really aimed to just make friends without expectations and see where life leads us. This isnt a race and we are aiming for true companionship, not just flings. So in some way I feel he is intimidated that I am really quite interested in my friend and we have fully discussed the dynamics of our relationship, while he isnt quite at this point yet. I think him and this guy met and had a bit of a whirlwind and assumed it would turn into something more. But now are dealing with the fact that they have to discuss our poly lifestyle in more depth, probably something he should have done beforehand.
I know we have been feeling SO good about this choice to do this, and this is our first real stumble. I refused to let him run away scared though. He knows he is under no pressure to participate in the lifestyle if he chooses not to (which he insists he still does
) and that I wont allow this to affect the relationship that Ive been working on growing with GF. We are doing amazingly well at communicating, so I think we will just be focusing a bit more time on that and helping him get more tools to deal with these types of situations instead of panicking. Thanks again