There have been times, especially early on in our marriage and only in the actual presence of his parents, that I felt like a second priority. We were able to talk about this however and came to a better understanding.
Since my husband doesn't participate in their weirdness and he is often mortified by their behavior, I don't really feel like he puts them above me or our marriage. In fact, I often think that - well, how to say this - that he reacts to them as if he were not their son, but their son in-law.
He never makes excuses for them and he never has. He usually says to me things like, "I'm sorry my parents are such freaks." I keep trying to break him of accepting blame and responsibility for them, but they taught him from an early age to do this and it is one tough habit to break.
In addition to their father's N antics, their mother did something different and which I consider deeply wrong. She encouraged the boys to take the blame for anything and everything, because their father was "too sensitive" to handle it. Like when she discouraged her eldest son from quitting peewee football because as she said, "your father probably won't have much to do with you anymore." Her son continued to play even though he was much smaller than the other boys and afraid. Two weeks later he was hospitalized after he got a concussion on the field. The coach, not his parents, finally said "enough is enough."
To be honest, this upcoming visit took both us by surprise. After they left this Christmas, my husband said he would understand if I decided never to see them again. I told him that I would never invite them to my home again and that I was never going up to visit them again if I could possibly help it. None of this was said in anger and having decided this, we figured that we could get away without seeing them for a year before they next visited.
My SiL says they are coming down because it's easier on them to be united against us than tearing each other apart in the privacy of their own home.
Short of actually moving and leaving no forwarding address (ha, ha), I'm not sure how to keep them out. I'm really not exaggerating when I say that they will come anyway. What do I do when I open my door and see them standing there - clutching all their clothes and toiletries in plastic grocery bags, since they are too cheap to buy luggage? Use that great Jack Nicholson line, "Sorry, we're all stocked up on crazy here"?