I, too, avoid them as much as possible. I try to perform as much care as I can when they aren't present. When they are present, I keep myself busy charting.
If they try to invoke me in their family drama, I normally flat out tell them that it's none of my business.
Any drama, yelling, etc. that affects the pt is well documented.
I try to start out friendly, but firm so that they know where I stand from the beginning.