Once you know the signs, they are easier to spot. If you can't avoid contact, it's helpful to know 'who' and 'what' you're dealing with . : )
I have learned a long time ago how to spot the signs and I do avoid those types. This acquaintance I speak of was someone that I got stuck with after my mom passed away and I felt a little obligation because of owing it to my mom. I recognized that she was a passive-aggressive, narcissistic type of person a long time ago. I know it would not end well as Like I mentioned you could not say NO to her. So the last straw was about a month ago she asked me to come over and do her a favor. That afternoon she phoned me and asked if I was coming over. I nicely explained that I could come over for about an hour but i had a previous commitment that I was going out to do something with another friend. She just said well fine forget it and hung up on me. (The passive-aggressive coming out.) This was the finale straw as this isn't the first time she has done this crap. Then the next day she leaves me a big long telephone message about how I let her down etc. No apology or anything. So like I said this was the finale straw and I cut out all communications with her. So now she knows that she is not going to get her own way and as a last desperation she starts getting real nasty. That is when she starts pulling up things I supposedly did twenty years ago, that she knows nothing about and starts threatening me. Just an ugly bitch and I am glad she is out of my life once and for all.