The uncomfortable "question" wasn't really a question, which may be why it's not being explained very clearly. It was along the lines of saying that Dean had "jungle fever" because he slept with Cassie in Route 666, and that since then Dean has "broken the rules".

Jensen wasn't sure what she meant by breaking the rules, so the woman clarified that Dean was breaking the "rule" of "once you've had black, you never go back." The whole thing was decidedly awkward.