Avoid the awkwardness of asking one too many questions by
saying up front that you understand a lot of questions can be trying. If
you sense that is becoming the case, simply ask: "I sense that another
question will annoy you, right?"
Most people will say, "No" which is your cue to go ahead -- ask
another question! If they say, "Yes" innocently ask who you might talk
to get your other questions answered.