I behave bad all the time and I always want to kick myself (sometimes I do!) afterwards. Or even while I'm saying said stupid thing in my head I have a chibi-lindsay that is super deformed going "sttoooooppppp!!!!!! NOOO!" and then it berates me for opening my stupid huge mouth.

Sometimes you just let things slip because I don't think I know anyone who is thinking 100% of the time..most of us it's like in the 30's range I think.

I think just the fact that you feel this badly over it proves that you are a really nice guy who just messed up a bit. It could have been worse and since your remorseful about it you aren't being a jerk just someone who opened their mouth and spoke very inconvienetly!