I have been through a year-long false R, and it took a combination of factors to survive it. It was ugly; I told both our kids--actually made my H tell them (the kids were 17 and 20 at the time and didn't know anything about the A until this second Dday. They did know that I was acting like a witch and that their dad and I had been fighting for a year). On Dday 2, for the first time in almost 2 years, I told my H I was completely done--AND meant it. I soon changed my mind, but when I first said it, we both knew that I was serious.
After Dday 1, my H had given me open access to his phone and work calendar, but in all honesty, I never routinely checked them, or I would do so immediately after he told me the passwords; I think I was so naive after Dday 1 that I really could not imagine he would cheat on me ever again--I was still frightened, but wanted so badly to believe in him that I set myself up for failure; I refused to see who he had become during the A, and chose to look only at the man he had been for over 20 years before the A. After Dday 2, he changed his phone #, showed me where and when he had routinely met the MOW, called the MOW in front of me and told her the A was over, encouraged me to call her BH (something I had not done after Dday 1) and sat beside me as I did so, taught me what to look for on his new phone and Outlook to see if he had enabled any type of messaging capability, took a polygraph, and honestly agreed to provide me all the ugly truth of the A--no more TT. In short, I finally implemented a modified version of the 180 and understood that the man my H had become during the A was not the man who had been my best friend for over half my life.
While all of the above sounds like I did something right, I think it's more fair and honest to say that I just finally started to take better care of me. I needed to feel safe and followed my instincts about how that could happen. It was incredibly hard for me because of serious co-dependency issues, but I knew I simply would not survive another Dday--seriously would not make it through another one. So, the actions I took weren't really about my M or H, they were about me and my survival. I truly understood somewhere deep inside me that I couldn't "make" my H do anything he didn't chose to do--I could only worry about me.
As for my H's side of the equation, he initially chose the MOW over me on Dday 2. That only lasted about 2 hours, and we both now understand he really wasn't picking her or dumping me; he was actually just letting both myself and the MOW make his decisions, just going with the current and feeling relieved that all the bs and conflict were finally over. He quickly realized that was only immediate relief, but a miserable and undesirable long term solution. And, in my opinion, one of the most crucial factors in our R, was my H really decided to and committed to walking away from the A. He finally made up his mind and committed to his actions wholeheartedly, without any reservations. No matter what I did, he had to make this decision first and foremost, just as I had to make my decision to keep myself safe and sane. This doesn't mean that I didn't require transparency, honesty, support, and care, it just means that I didn't require them only to save my M--I required them to save myself.
One final caveat: I further believe that it was important to really look at who my H was/is. He was an incredible man, partner, father, friend, etc. for over 20 years prior to the A. His core was good, and I knew it. I believed in his ability to return to himself if he chose. I believed the A was the anomaly, not our M or my H. He was worth the risk of another chance. And I am so very grateful that we both made the most of that chance.