I should clarify; I'll call him "her" to his face, not in other situations. Sure, I'll pander to his mental illness because I don't want to drive him over the edge. Same as not bringing up to a person with Alzheimer's that they've already told me the same story six times in the last ten minutes.

Anyway the guy's only a passing acquaintance and the last time I saw him and said "hi" was probably 3 or more years ago, so it's not like I have to spend a lot of time indulging him.