Hmm, sometimes it takes something like this to see what someone is really like. I had a friend who had been a friend since we were 3. We had grown up together and been almost inseparable through childhood. We had one fall out when we were 16, basically because we'd been doing different things and grown apart. I was happy to welcome her back as a friend a couple of years later. I sent her a birth announcement when ds was born and after not talking for 18 months we became almost as close as we had been before.
She has been away a lot, at Uni, a year off travelling, working away, etc. We met up about a year ago and went out for the evening. After a nice evening at the cinema, we got into a debate on the drive home about principles and ethics etc. She basically criticized everything I believe in, saying I was naive/stupid/a hypocrite, etc. The worst thing for me was a comment about parenting (bearing in mind she has no kids and very little contact with them), we were talking about the fact that I was home educating my kids. I asked her why she has such a problem with the idea of home education, her response 'I don't have a problem with home education generally, I have a problem with you home educating'.
I was (fairly understandably) very hurt and upset about many of the things she'd said. A couple of days later she contacted me again asking if I wanted to go out again next time she came down. After lots of soul searching and wondering if I was being really petty, I told her no, I didn't think it was a good idea. I didn't want to not be friends with her, but thought it was a bit pointless meeting up as we always seemed to argue. I've not heard from her since.
I still feel slightly guilty when I think about her, but on thw whole cutting her out of my life was the best thing I could have done. It's only with hindsight that I realised what damage she did to my self esteem. She was always putting herself down, but always managed to do it in such a way that she put me down too. I felt quite liberated releasing myself from that!
I know it's not the same as your situation, but I think it can be all too easy to fall into habits with people who make you feel bad about yourself. Sometimes, painful as it is, something which draws your attention to that is a good thing.
Having said that, I'm a veggie and if anyone deliberately fed me meat I would never, ever forgive them