[Jane52]

I agree with TH. If they have been asked if they want to order an appetizer together with you and they said "no", then they can watch you eat what you ordered for yourself.

But for the sake of marital peace and not embarrassing your wife, maybe you could do this:

So you don't get the almost empty plate with 2 pathetic morsels of YOUR appetizer left at the end of it, how about this when it's brought:

Put half or 1/3 of it on a separate plate and say, "If you'd like some of my appetizer, here is some of it to pass."