A coworker just told me this:
She had a dinner party over the weekend and invited her parents, her ILs, her and her DH's siblings, and a few close friends - I think it was maybe about 15 people, total. She spent the weekend preparing an exquisite meal and planning everything so it was just right - the decorations, the food, the beverages, centerpiece, etc. No detail was overlooked.
When she invited her guests via phone, a few of them asked "would you like us to bring anything?" No, no, she responded - everything was covered, and she just wanted them to bring themselves and their appetites. My coworker is also known for making her table 'groan' under the weight of so much food, and even the pickiest eater can find quite a few things to eat.
Her SIL showed up with a plate of Jell-O that she demanded to be placed on the table and served with the meal, even though it really didn't go with the meal that was served. It wasn't a casual "hotdogs and hamburgers" sort of meal, for sure.
My coworker tried to say "oh, thanks, we'll enjoy this tomorrow" and put it in the fridge. SIL went to the kitchen and put it on the table, and yes, it looked out of place. I guess the atmosphere had gotten uncomfortable, so coworker decided to just let it go.
I find the SiL's actions to be appalling. FWIW, when my coworker goes to dinners that her husband's family serves, they usually have cook-outs and whatnot. Nothing wrong with that, but my coworker wonders if her SIL is trying to 'say something' by showing up with food and demanding that it is served. And even if my coworker was having a more laid-back sort of dinner, I still think it's rude to show up with a prepared dish and foist it on the host/ess. Who knows, the host/ess might have planned a meal specifically around a guest's allergies? It also comes across as "you don't have enough food/you can't host properly," but I thought I'd ask you all your take on it. Have you ever been in a situation like this? What did you do? Do you think SIL was in the wrong?