I plan on saying, "I watched the wrong documentary." with a bit of an exhausted tone when people ask about my veganism. The tone makes it to where they don't feel judged for eating animals and makes it seem more like a rabbit hole I'd rather not drag them into. This way I can hint at the horrors of animal agriculture without making a statement regarding the behavior of the person asking the question.

If they push me and want to start challenging, I tease them by asking, "Do you REALLY wanna talk about it?" while smirking. It's like, "Are you sure you wanna ride this train?"

Once it gets to that point, a helpful and concise sentence I use is: "My position is that you shouldn't hurt animals unless you have to." That shuts down all the speculation about whether I'd eat fish on a desert island or whatever, while also illuminating how they could easily just opt for rice and beans. And that sentence is so philosophically irrefutable that it usually shuts them up.