I had dinner with RO. We fought. We didn't concluded the fight. It was a polite fight, but I didn't give up in frustration or go silent. Afterwards I got the following from RO's daughter...

Hi BC. I heard you and dad had dinner and a good talk. There aren't words I can say to express how happy I am that he is healing in his mind, body and soul. You are helping make that possible in every way and I am so very grateful. You are a kind and generous man, and my father is lucky to have live and loved with you. Thank you for taking the time to talk with him tonight. Speaking openly with you is something that is helping him move on in more ways than one. I hope that you are doing well, and that you know that you can call and ask me for anything that you might need help with (although it seems that you have it under control). Love and big hugs to you! 

I responded...

Thanks. I would like your advice. I worry that when I spend time with RO he gets more attached and more depressed. So your feedback is welcome.  If he is getting better then great

But please let me know

 She answered back...

It was as if he understood things clearly for the first time tonight. That you didn't end the relationship to hurt anyone, that it was just what you needed to do for yourself. He really seemed like he was in a good place. Almost as if he felt weight lifted off of him. I hope you felt good after your talk, too. I would definitely let you know if he was getting more depressed or acting out of character again.

This is good. It's also given me food for thought-- that there are times where a dangling argument is healthy. Not giving in. Not in the winning. Not in consensus. Sometimes it's good for two people to disagree and to know they disagree and for each to know that the other won't sway. 

More than once people have pointed out that I "avoid conflict." Of course I've thought. There is nothing wrong with that. Get together with them. Talk it out. Make a choice. More often that it should, this strategy just means I avoid people and issues.

Now there is a third way. You may not need to decide that one position is right and one position is wrong. Both of of you are free to go your own way.

I'm in my mid 40's and a manager of a big team at a large company. Yet, in the past month I've learnt more about interpersonal relations that I have in 40 years and have become very aware of how much I have yet to learn.