In fact our priest has said it is better, more loving, more Christian, to just eat what is placed in front of you than to call attention to it, refuse it, etc.
I truly think this is the best thing. My in-laws, for example, God bless them, are not the most thoughtful of people, especially in matters of food. My mother-in-law is Italian and she thinks like Aunt Voula from "My Big Fat Greek Wedding" (What do you mean he don't eat no meat? Oh, that's okay. I make lamb!"). They sometimes do remember not make a meat dish or to at least prepare some extra vegetable dishes for me when they invite us over for dinner at fasting times, but, for the most part, it just slips their mind. On more than one occasion I've had to stop my wife from picking a fight about it because, in the end, that would be a far more embarrassing and sinful thing to happen than for me to eat a small portion of meat enough to be polite.
There have been times when they've checked themselves upon noticing that I'm eating less than usual or whatever. They then profusely apologize about it as if I were a Muslim and they've just served me pork sausage without telling me. That's just as bad, I think.
For the most part, they've gotten better through trial and error, but I am a firm believer in not making a fuss over it unless I have complete
control over the menu, which only happens in a restaurant known for vegan cuisine (they like to eat out, too) or if I'm cooking at home.