i've bin a veggie for around two months now, but if i went to dinner at someone's house, and they had cooked me fish or meat, i would feel more guilty about refusing the meal than i would by eating the meat. i wouldn't feel comfortable, unless i knew them very well, about telling them before hand that i was a vegeterian. if they're prepared to go to the effort of cooking for me, why should i make them even more work? i was just wondering if other veggies have the same approach as me?
I usually find most people are quite happy to cater for a veggie. If they're not, then I don't go and eat at their house. There are other solutions though - you can offer to take some food along that can be chucked in a microwave and reheated. Or depending on the meal, then they can just leave the meat out of your helping.
what i usually do is i let them know that i'm veggi before i go over, and i tell them that i can bring my own food. if they're desperate to cook for you they can always tell you not to bother bringing your own food, and then you don't have to feel like you've made them do more work either.
I would not eat the meat. Everyone knows now I am a vegetarian, so people don't even ask anymore if I will eat certain meats. They know I won't eat any meat. I will eat cheese and dairy products. I could never EVER give that up.
