Reb E, the term desensitization is most commonly used to describe a numbing to something which normally stimulates.
I’m using it to describe someone who’s numb to how far he is from kedushah after years of sewage being dumped into his eyes and brain. Be thinks movies don’t affect him.
You’re talking about someone who doesn’t feel gashmius; I suppose the word desensitize is technically fitting, since he has no sense of the stimulus, but it’s for a completely opposite reason.