I think.... you SHOULD be able to be with your family.
AND your Husband... has to let go of his rigidity....
HE is their Son-In-Law TOO... and he has a duty to them too....
Exceptions... needs to be made.
SHOW your Husband... your posting and all the responses you get back.
Sorry, but only having 'dessert' with your Family IF there is time, per your Husband... is not good enough.
Your In-Laws... are rude.... and selfish...
MY Husband... would understand.... even if he is quite traditional.
And frankly, bluntly... I would be pissed... if my Husband prevented me from seeing my family/siblings... and only offered me to see them only for dessert IF there is time...
Geez.
AND... HE needs to show face too... to your Family's Thanksgiving.... that is his "Duty" too... as a Son-In-Law. If not... and he doesn't show up... that is real rude, to your family... too.
Frankly, if I were one of your siblings... and you hardly saw me otherwise... and "your" Husband said you cannot be with them at Thanksgiving and only MAYBE for "dessert"... I would not like your Husband....
As you said... your Siblings... are RARELY in town or able to come.
THIS year, your Husband needs to make an exception.
AND besides... he should NOT be dictating this.... it is a JOINT compromise.... and I would think he can make the 'loving' choice to compromise...
He is your Husband... it means a lot to you... and he is not a child... his first priority... should be to you... for you.... to see... that this year is an exception...
The Holidays are special... and it is for you since your Siblings will be there... so, that in itself... MEANS that you SHOULD be with them... and your Husband... should stop being a stick in the mud.... or a Mommy/Daddy's Boy.
If your In-Laws cannot understand your needing to be with your Family... then that is their tough luck. You... have a family too. It is not a monopoly.
And THEY SHOULD BE... respectful of your family too... that is PROPER manners.... to show respect... to their Son's In-Laws too...
And besides, your Mom... is hosting your family's Thanksgiving... you SHOULD be there... too. And with your children... your family AND Siblings deserve to see them TOO. Since they are not often able to come.
And as you said... your In-Laws are the types that only go by their schedules or their kids. They change things at the last minute and expect you/your family to change your plans at that last minute. That... does not seem like they will, willingly... work with your schedule or your family's timing of Thanksgiving meal....
all the best,
Susan