Whats so hard about it?

I get that not everyone feels the same way that I do about blended family's. I understand that when dealing with blended family's it can be a very hard thing as each one "blends" differently. Dave and I are very vocal and upfront about how we handle our family. Its quite simple ~ there is ZERO distinction between our kids. We expect the extended families to treat each child exactly the same. Wither there is a blood tie or not to them. Most our family "gets" that, and amazingly most are pretty good about following our "guide lines". Some however just don't get it, and truly it frustrates me. I hate having to "correct" family when I see them being unfair to the other kids. I'm sorry but I don't sit back and let people destroy the unity that we have created. We have one set of grandparents that are just now ~ nearly three years into our relationship ~ who are trying to understand it. Why is it so hard? Why is it so hard to accept that while you share no blood with this person they are in fact family now? I don't get why it has taken so long either. Well I do ~ they refused to accept any part of our family until they had no other choice. But that is a topic for another day. Tonight these said grandparents came to visit. These visits are very testing for all of us ~ there is a lot of "bad blood" that we are trying to let go for the benefit of our children who do have attachments to them. While we are trying to do the right thing its so very hard sometimes. Especially when you are having to correct the grandparents behavior ~ and trust me they are VERY unwilling to change. I know it will get better with time...hopefully. But I have to try and be positive. Even when in truth I want to give them the boot and say that our children have more then enough people who love and care for them, and we don't need your bull!