I finally have time to share the story of our first Christmas @ my FIL's... He is remarried so thankfully I didn't have to deal with my batshit crazy MIL...
HOWEVER, my FIL's new wife is a different kind of crazy. LUCKY me

Although we LOVE my FIL we typically visit when we know his wife will be @ work b/c neither of us can stand her.
Everything was going great and I say to the step-MIL "Oh hey the corn casserole is good, (even though I know her niece made it, she had to brag that it was HER recipe) I've never had it with sour cream. Her reply is an eye roll and a snort! WOW ok.... Then after dinner my hubby is moving to another table to sit and chat with his brother, who recently had a stroke and is having difficulty holding his fork steady, and she insists that she pull out the table so he won't have to squeeze past the wall to fit. He actually had to raise his voice and say NO PEOPLE ARE STILL EATING AND THAT IS RUDE!. Then as we're all sitting around having desert and my FIL is sharing a piece of cake w/my toddler she comes up to him to ask why she just got off the phone with her (insert random family member here) who says he told them NOT to bring by the chocolate cake she asked her to make for them... He replies nonchalantly with well she had ppl over so I told her to stay with her company as I had already bought a chocolate cheesecake anyway. She says oh so it was a miscommunication? He says rather annoyed No it wasn't I told her not to come. she asks well why b/c I asked her to make that cake and you made like we didn't want it... He says I don't give a rats ass, who cares? She yells (directly over my head now) Well you should give a rats ass cuz it's RUDE!!! And storms into their bedroom and slams the door... WTF who does that with company in the same room? so everybody is like Well time to go! lol (Imagine the scene in The Color Purple where Squeaky slaps Sophia)