You're not wrong, but I err on the side of "aw, let it go" with this kind of thing. If he had fun doing it, if it helps his morale, that matters more than our moral griping, I think. Keep in mind the lockdown and the general horror and chaos of our world and how people are dropping like flies because of it. So we have to perform self-care and if making irreverent jokes like this helps him, I think God will forgive.