I said: "I'd like to ask you not to joke about triggers and trigger warnings. Folks with PTSD get ridiculed enough as it is."
He said: "I respect you very much. And I respect what you're asking me, and why. I have a very big problem with the concept of 'trigger warnings.' And that may be because of how I was raised, or things I was never exposed to, or because of my own views about jokes, free speech, and so on. Which is not to say that I'm correct in any of it, or, certainly, that I don't have a lot still to learn. But it is a factor in who I am and how I act and what I say. Because I would never want to cause any person undue harm, I will think about it."
I said: "Thank you. Because being triggered by something causes actual harm to the people who experience them. Think of a trigger warning as like an allergy label for someone with a severe peanut allergy. It's not a spoiler in a movie review. It's a notification that the content could be actually harmful to some folks."
I said: "It's not really up to people who don't have PTSD to have opinions on trigger warnings; it's a bit like able-bodied people having opinions on whether a courthouse that has no wheelchair ramp should warn wheelchair users ahead of time that they can't get inside."
I said: "Another thought is the 'punch up, not down' theory of comedy. Make fun of people who are better off than you, not worse off."
I haven't heard from him since.