He's out of questions to ask, and the connection is still live, he can feel it there.
What Keltham does then is not very Iomedan, it's foolish to act spontaneously in a conversation with a god, he hasn't calculated what this question or his feelings while saying it might give away -
"Would you feel sad, if I stopped being your cleric, not just a loss to your utilityfunction expectation, but, sadness?"