I have to discuss these things with my DH before the event because he does not understand how much work is involved, and the social nuance often evades him.

I'd advise you approach it unemotionally and logically with your DH. Lay out what you did, how you felt, and if it's to happen again here's what HE needs to do to make sure it's a lovely time for everyone. You are not to do it all! He's part of the couple!

The last party DH and I threw is the last in a long time. In spite of DH knowing what he needed to do, it came down to me at the last minute. He didn't help set up, or clean up. So I told him that if he wants to host again then it's 100% on him. He's been good in the past but last spring was just ridiculous.

Yes, I agree with you. It matters how your DH treats you in front of his family. If he can't treat you with honor and respect, he doesn't deserve you. My mother used to describe men as "bears with furniture,"meaning they often do things simply, and miss much of the social nuance in life.

Iyour

If your dh doesn't get social nuance, tell him exactly what you expect of him at these gatherings.  If he doesn't comply, let him do the cooking, cleaning, etc so you can steal the best seat and take all the credit. 

And zero rewards.

Last night, Husbands older sister hosted everyone. We had had an argument on the way there, so I slunk in and sat in a chair watching. No one offered to help her. No one helped with cleanup. Everyone sat or stood around drinking and eating. No one honored her in her own home. It might be a culture thing. The king in his castle with his minions while he looks like gold.

I think you should tell him at once so it sinks in.

Similar has happened to me. All the things must have magically happened because I was invisible. He was too busy entertaining adult kids, being the cool dad.

He never wants to experience the fallout of my major meltdown again. Since then we discuss prior and we check in with each other periodically throughout the event. I had to specifically tell him that he needed to make room for me in any conversation he was having if I joined his group.

You definitely need to discuss with him how you felt and what  he can do to make it a better experience for you next time. See how he reacts. 

 Then I ask myself, what did I want DH to do? Is it too much to ask that he wait for me, seat me and then sit himself? Or is this just too much sensitivity and resentment built up? Am I overreacting? 

No, you are not over reacting.

In fact, I would sit DH down for a come to Jesus meeting informing him that his rude behavior abandoning and ignoring you, moving your place at the table, and absolutely failingto help, support, honor, highlight your effort, keep his rude spawn and their families in their place, etc, etc, etc... will never happen again because you will NEVER cater to him or them again.

PERIOD DOT!

Hinting, waiting for them to find clarity, hoping, dreaming, praying, etc.. is an absolute waste of time with these types. The full meal deal, bare their ass, in their face, scrub their noses in the stench they stain their life's carpet with is the only way to address the issue.

Never again and full real time bare their asses confrontation at the moment of the infraction works.  Invest in that.

'Who ever moved my place, get up, put it back immediatley, and here, take your spawn and deal with it yourselves, and when dinner is through, clean up, do all of the dishes, put them away neatly in the proper place and if you ever want to be back for an event, never forget that rude crap will not be tolerated.  DH, you will make this happen now and you will enforce these stipulations if you ever want your family in MY home again. Merry Christmas!'

smh

You are describing my Christmas for many years - work myself to death for what?  Nobody noticed.  I've cut way, way, way back and guess what?  Nobody notices or cares.  

Nowadays, I do what I want to do, people show up or not.  Or they invite us, or not.  It's still a difficult time but I'm less tired and stressed altho can't wait to get back to my normal routine.

I couldnt agree more, the holidays are seriously overrated.  December is far and away my toughest month.  It takes me all year to either get over it or prepare for it.  The worst part is DH and I always have a fight altho the rest of the year is peaceful.  Sigh.....

your part is done. get out, go do something. even if it's going to the library for the day or a museum or a anything. just go out for the day every day until they leave.

and after they go tell hubby that this year was so much work for you to do alone that you've decided that next year it's either pot luck or shit outta luck. he has a year to figure it out. 

Unless this is a casual buffet type meal.. usually people wait for everyone to join and say a prayer or whatnot.. together before eating.

I don't think it's necessary to sit beside a spouse.. in fact many people would mix up the invitees so that hosts would split attention to the other guests.. so the seating per se would not be a total issue.. if you were seated with your mother.. and his daughter with him.. I could see that being reasonable since both hosts would get to sit with people they care about that are not normally present in the home at meals.

But for everyone to start without you is generally rude.