The Repercussions of Slipping focuses on what to do so that, rather than having dead bodies on the side of the road, your path is lined with joyous, thriving relationships. Not a bad goal, is it?
Are all relationsips equal? Certainly not. However, if they are not toxic and detrimental to your well being, look for some redeeming factor and focus on that. This does not mean being a door mat and taking abuse. Rather, set limits for yourself and remove yourself if the conversation turns negative. Practice the positve with whomever is acting negative as an experiment and see what happens.
If all else fails, set your expectations for the relationship at a lower bar. Converse as acquaintances rather than true friends.
If your goal is to be impeccable in your conversations, play with ways that you can stay focused on being in your integrity, using right language (meaning ethical, respectful, kind, relational), and finding the right kind of relationship with this particular person. I'm using the word right to mean appropriate for you rather than using the terms right or wrong to indicate good or bad.
Find out what will work for you so that you can be authentic (using different facets of your diamond) with the focus of remembering that you get to choose if you want to be 'right' or be happy. Do you want a road lined with dead bodies? Or do you want to look down a path lined with relationships that span your lifetime?