try (one's) patience
To frustrate or annoy one by continued unwanted behavior; to test the limits of one's patience. His tangential questions are clearly trying the professor's patience, who asked that all questions be held until the end of the lecture. Will you take the kids to the playground for an hour? They're really trying my patience.
try someone's patience
to strain someone's patience; to bother someone as if testing the person's patience. (Try means test here.) My loud neighbors are trying my patience today. You really try my patience with all your questions!