I agree with melissag - the conversation may be brought up by your H and you need to have a plan on how to respond. I have stopped bringing up the future and our M, but H will still work things into the conversation. For so long my H would stay that he hates our marriage and I would try and defend out marriage and explain why things had gone wrong but could be better. Now when he mentions it, I simply say that I understand and that I also do not want to go back to that marriage. You are not saying that you dont want to be married to your H, just that you dont want to go back to THAT marriage, the one that never of you were happy in.
Your interactions will continue to be really tense and awkward. They have a wall up and will continue to keep it up if they think that you are going to try and talk about the M or will break down and beg for changes. I have found that our interactions has gotten better with time. We have gotten to the point that we can even joke around with each other a bit. It is still awkward sometimes, but much better than before.
Focus on you, focus on how you want to interact with H. If you are friendly, H will follow your cues and will start to be friendly back. Just realize that H will take a lot longer (A LOT LONGER) than you think to follow them so be patient.