Hi Artemis, I think the "friend" thing when it comes to a wayward is often misunderstood or misinterpreted from Michele's books. I don't think Michele or anyone here would ever recommend that you be the "best friend" of a cheating spouse. Being the lighthouse, taking the high road, setting an example for your children, those are all things you should absolutely do. But those are not the same thing as being your wayward spouse's best friend, or even being a friend at all.
When I went to Retrouvaille, one of the coach couples were an example of what I believe Michele is espousing in her books. The husband went wayward, it was completely out of character with who he had been before in the previous 10 years of marriage. He started staying out late or even all night. He partied, he had affairs with multiple women. He owned a business that started falling apart. He drank heavily, he dabbled in drugs. He begged his wife to leave him and kick him out of the house. They had 3 kids, throughout the ordeal she was an amazing mother to the children. She refused to kick him out or leave him, she told him that was his decision to make but that she was not going to abandon the marriage no matter what. And she was not going to make that decision for him, he would have to do it himself if that's what he chose. She took care of the home, she took care of the children, she never complained about her H, she never said one word about his activities to others or disparaged him in any way.
But she was NOT his best friend. When he would come home smelling of booze and women she did not welcome him into the master bedroom. She showed him love without validating his poor behavior. She made it clear the door was always open to reconciliation, but she also made it clear his behavior was going to have to change before that could happen.
Eventually he hit bottom and begged her to forgive him and take him back. And she did, but not until he had done a lot of hard work on himself and on the M. The husband was the one that told the story through tears, it had been 15 years before that it all transpired and he still felt terrible about it. He said he didn't know who or what he had become, and even at his worst he couldn't help but admire and respect his wife for her ability to hold it together and conduct herself with dignity and respect even while he was trying to drag her down to his level. That was what eventually brought him back.
I think that's the real message of DBing. Conduct yourself with dignity and respect but don't be a doormat. Your H has to go on this journey and all you can do is step back and give him the time and space he needs for that journey. It may bring him back or it may take him somewhere else, that's outside of your control. But if you DB properly then you will be prepared no matter the outcome.
