A man will try to avoid a verbal argument as far as possible, therefore, when he says what is on his mind, chances are good he did not expect it to turn into an argument. Before chewing off his ear, take a breath and apply patience. What he is saying may be a bit hurtful at that point in time, but if you want to encourage honesty you will need to hear what he says. Who knows, you may need to do the same in future.