Should probably name change but oh well. I have posted about this once before, about a year ago and I've stuck it out until now, BUT...
Lifelong friend, generally nice person, but one of her two DCs is utterly horrible to be around. :( I know, it sounds awful to say. It's well past being a phase, we're talking years now of incredibly obnoxious behaviour. Obnoxious is the exact word but can't begin to describe how extreme it is. Friend says that her DC are "free spirits" and does not try to curb it at all. Her other DC is far better behaved.
My DH does not want to associate with her & her DH at all because of this and I can't blame him. He'd prefer our DS not be around them because of the things that he picks up and we then have to explain why we don't do these things.
A year ago I received advice on here to try to see her without DC. Well, shortly after I posted that she told me about wanting this DC to spend lots more time with me, what a good role model I was, etc., so it made the advice tough to follow! I haven't wanted to give up on a v. long term friendship and I have tried so hard to grit my teeth and bear it but 
I just cannot stand to be with them anymore!!! It is so frustrating.
We are good enough friends that I have tried to speak to her a couple of times about the behaviours. Problem is that we have completely different parenting philosophies and she really sees a lot of the behaviours as "self expression" that she doesn't want to "quash." I, on the other hand, see it as rude/ill mannered/generally obnoxious.
I really didn't want to lose her friendship over this but I just cannot see how we can continue a friendship when I dread seeing her and now find myself constantly making ridiculous excuses to avoid her, except on rare occasions when I know she will be without said child. She really does have a good heart, she was one of the few friends who stuck around when I made a big (positive for me) life change a few years back.
So if you've gotten this far, AIBU to give up on the friendship? There isn't really much left of it anyway at this point I guess, but I'm :( about it.
Be brutal, I feel like I deserve it for even asking, but between having my house destroyed and listening to an endless stream of incredibly rude drivel, I am at my wits end and genuinely have no idea where to go from here.