How often do you say something and immediately wish you hadn't? I do at least once daily. Although, over time, I've learned to pace myself. Think before I speak. But on those occasions when I realize that my words have unintended consequences, or worse- my comment indeed makes the exact blow I intended, I'm disappointed in myself. I know better. I've been on the other side of comments that have stung, and I hate it. In those moments, I tell myself I'll never treat someone the way I've been treated. And yet, inevitably I make the same mistake again.
Patience is required when handling a sensitive topic of conversation. Speak less and reap the reward.