I used to be a vegan. I went hard for three years. I didn't even eat butter or honey (a lot of "vegans" cheat and eat all sort of animal products). I didn't drink beer or wine that had been processed with fish derivatives (this is common). I was a crazy vegan. It was like a religion.

There isn't any point in getting into an argument with vegans, just politely wait it out. Take it from me, veganism is a problem that takes care of itself. You can't survive without meat. Eventually you have to go back to it. So if you have a loved one whose "going vegan" it's nothing to worry about. The problem corrects itself and in a few years ya'll can laugh about the phase together.