Censoring myself

I am incredibly direct. Most of the time, I don't think I'm rude (anymore - I admit I've had to work hard to learn how to be more diplomatic); I simply have a hard time not saying what I'm thinking. And there are times when I forget that, as a teacher, this is not a good thing. I'm pretty sure I've never been publicly rude to a student but in class last night, I reacted without thinking to something a student said and the more I've thought about it, the more I feel stupid about it. I wasn't actually reacting to the student himself; he used a term that I haven't heard in a while, that he had obviously learned in another economics class, and I was thrown off because a) it took me a second to figure out what he was talking about and b) when I realized what he meant, it told me something about the way one of my colleagues must teach a particular course. I laughed, then realized that the student might think I was laughing at him, so I felt like I needed to explain why I was laughing, but I think that only made it worse. It was an awkward moment at the time, and I feel even more awkward about it now, but there's not much I can do about it about at this point except try to remember to think a little longer before I open my mouth...