I treat them normally if they do not try to impose my way of life on me. I eat meat and I like it, because the body needs all trace elements. Perhaps in the future I will reduce the amount of meat, but I can not completely refuse.
That's the problem with a lot of the Vegans that are present today, at least the ones that I've met. The big thing that they love to do is to shit on all of the foods that you eat and they love to compare themselves and their eating habits to you, which is something that just bothers me.
If Vegans want to do what they want they can and I won't care, but once someone starts bothering me on what I do and what I eat that's when I personally feel that they've crossed the line and are going to have to take one step back.
So, Vegans are fine unless you bother me about my eating habits.