K.P.
I just zone-out. Serioulsy. My in-laws think that public education... well, let's just say that they forget that I work for the public school system and don't feel a need to "filter" themselves in any way. They also don't believe in daycare or working mothers... you can see where this is headed.
I usually just grab a glass of something (this year it will be cider) and just pretend to listen. If I am asked a direct question, I answer. Otherwise, I just pretend and nod. I also bring something crafty for the kids to do while they are waiting for dinner. I take them all into the other room and we make ornaments or some other decoration. Not only does it make me the "fun aunt", but it gets me out of the middle of the insanity!