I am being deliberately vague here to protect who everyone is while keeping them straight and paraphrasing what was said...
The story below highlights how I treat and speak of others when they are not with me. This is how I act about all of my friends and acquaintances.
I was visiting a friend (Friend) during my lunch break yesterday, and while we were standing near my work truck (I was preparing some parts to be shipped back) a neighbor and acquaintance of Friend (Neighbor) came over to us and said to me, "I know you from somewhere." As we talked, we discovered that Neighbor had been in a class I had taught some years ago while I was a Mental Health Counselor.
Neighbor and I continued to talk, and the conversation turned to people we mutually knew, two in particular (Mutual A and Mutual B). Neighbor called Mutual A an "asshole" and Mutual B an "idiot." I replied, stating "Mutual A is strong-willed and is set in his ways about doing things. Mutual B has knowledge, however they lack the understanding to apply it properly." I did provide an example of Mutual B's "expertise." Neighbor pressed me, trying to get me to call Mutual A and B the same names he used.
It was at this point that Friend said, "Give it up Neighbor, he doesn't say things like that about anybody."
I am not providing details as to why so don't ask. I respect Mutual A and Mutual B, make no mistake about that. I continue to be friendly with them to this day, when our paths cross. To say that I like them, not so much. I have had occasional less-than-satisfying encounters with both. I can suspect, but I will never fully know their motivations and reasoning about why they treated me as they did.
I cannot change them, nor can I change their perception of me. All I can do is to try and be the best person I can be. How that appears to others and how it influences their opinion of me I cannot affect, nor will I lose sleep over it. That is their burden, not mine.
I defend everybody I know when I hear their character maligned. On Facebook, I have defended both Trump and Hillary when I see memes or whatever that state things I know are not true about them. If I have two friends/acquaintances who were in a relationship and broke up, I don't take sides with one over the other, and I ask one not to malign the other with me.
I have your back.