For example:
Carnist: "Hey, you want a slice of this pepperoni, triple cheese pizza?"
Vegan: "Sorry, no thank you, I'm vegan."
Carnist: "Oh, wow! Nice! I respect that! Yeah, I would go vegan, but I just would struggle with protein, B12, and iron if I did! Like, I tried being vegan for a week and got so sick! I still eat plant-based alternatives every now and then, though! And I totally get where you're coming from with your ethics! Yeah, the way they treat animals on those factory farms is crazy, bro! I hope those cruel practices can be abolished one day. Complete solidarity with you and the animals, dude! ✊ In the meantime, I absolutely try my best to get my meat, dairy, and eggs from local, free-range, humane, and organic farms!"
Vegan: "Okay?"
Like, seriously, just saying "Oh, okay." and moving on with your life would be preferable over this shit.
Yes! It is so annoying. Was at a work dinner recently and the person next to me insisted on asking about my diet, making excuses for themselves (and how hard they try, and ethics are complicated, etc), then apologized for eating meat near me.
I literally never brought it up. You are insisting you are doing something wrong, just drop it lmao. Not like I'm going to start something with senior people in the workplace over their diet.
It's a real tell about their own feelings and cognitive dissonance. Just existing as a vegan is enough to make people defensive, because by existing as a vegan you're showing that being vegan is possible. This shows people that they don't have to be aboard the carnist treat train, but they are.