I find it difficult when friends who aren't aware of my choice offer me things I won't eat - I feel rude when I say no, but find that usually they're understanding, and as I don't preach to them about their choices, we still continue to respect each other :-) If they start to try to tell me how being vegan isn't a good idea, and how eating meat is the best way, then I know they're not being very respectful, and they're not really my choice of people to be around. I'm ok with friends who eat meat, as long as they're ok with my choices too :-)