Tom Powers and Bill Wilson wrote the 12 and 12 together. Had a huge falling out due to Bill’s Sex addiction.

Tom Powers helped Bill Wilson to write Bill’s second book, Twelve Steps and Twelve Traditions. Francis Hartigan, who was Lois Wilson’s private secretary and confidant, recently wrote a biography of Bill Wilson. For it, Hartigan interviewed Tom Powers, and quoted Tom as saying that he had urged Bill to quit his smoking and womanizing:

“All the while we were working on the ‘Twelve and Twelve,'” Tom said, “I would argue with him, ‘you’re killing yourself. And think about what you’re doing to Lois!”
While other people I spoke with insisted that Lois never knew about Bill’s affairs, Tom insisted that “Lois knew everything and she didn’t have to guess about it, either. A lot of people tried to protect her, but there were others who would run to Stepping Stones to tell Lois all about it whenever they saw Bill with another woman.
I asked Tom how Bill reacted when Tom would insist that Bill’s guilt over his infidelities was responsible for his depressions.
“I think that was the worst part of it,” he said. “Bill would always agree with me. ‘I know,’ he’d say. ‘You’re right.’ Then, just when I would think we were finally getting somewhere, he would say, ‘But I can’t give it up.’
“When I would press him as to why the hell not, he would start rationalizing. What would really kill me is when he’d say, ‘Well, you know, Lois has always been more like a mother to me.’ Which somehow was supposed to make it all right for him to cheat on her.”
Tom himself had also been sexually compulsive even after he quit drinking, and he found it very hard to change his behavior.   …
Tom said that it took him five years after he quit drinking to change his behavior in this area, and for five years after that, he tried to get Bill to change, too. “Besides what he was doing to the women he was chasing and to Lois, his behavior was a huge source of controversy in AA,” Tom said. “He could be very blatant about it, and there were times when it seemed like the reaction to a particularly flagrant episode would end up destroying everything he had worked for. But then people would scurry around and smooth things over, or cover it all up.”
According to Tom, Bill’s behavior caused some of his most ardent admirers to break with him. Eventually, Tom broke with Bill, too.
“I told him that I still considered him to be my sponsor, but that I didn’t want to work with him anymore. I said that I hoped we could be friends, but I didn’t want to have anything more to do with him publicly. I just couldn’t go on feeling as though I was in any way supporting what he was doing to Lois — and to himself.
“Bill said, ‘Fine. I feel the same way about you, too,’ and we shook on it. As though it were some mutually agreed upon parting of the way, with fault on both sides. Which was a real switcheroo, you know. I think he knew that I saw right through it, but I guess it made him feel better not to have to take responsibility for destroying what had been a very enjoyable and productive working relationship.”