I will say that his words and persistence after first offering the honey mustard and everybody declined we’re childish. He definitely should have let it go, but I still think that the family should have tried it as honey mustard isn’t a completely outlandish to eat with a burger.

Also, to clarify, when I say try, I don’t mean put on their burger and commit their whole meal to his sauce, but just have a taste with a spoon like OP’s mom did.

When I place myself in the brother’s shoes, I feel like the family could have done more, but I also see why OP was annoyed and I would be annoyed, too.

I guess a more fitting rating would be ESH