My H had an A. And has cmoe back to me MANY times saying it was over with her and it would never happen again. And over and over again, I find out that he cann't stop with her. And frankly, I don't see remorse from my H. In my opinion, contact of any kind is unacceptable. That is where I am with my H. He came back AGAIN and swore he cut off contact, when in reality they're still at teh very least texting each other if not talking. That was it for me. Any R... even a friendship is unacceptable if the M is to succeed. It is up to your W to determine what she wants more... to save your M or to continue to be in contact with OM.
On the question of once a cheater always a cheater... i definately do not agree wtih that statement. I think there are MANY people who fall into the trap of an A. Like JM said, it's about learnign from your mistakes. We're all human and we all make mistakes. It's what you do with that mistake that counts.