The act of saying something completely inappropriate unintentionally. This is for scenarios where it is greater than mild word vomit and happens with more information that has somehow fallen out of your mouth.
Girl 1: I don't know why Jordan has been acting so weird. It's probably because he loves me and is feeling embarrassed about it.
Girl 2: It's because he slept with me. And he thinks you're crazy. And annoying. And he is scared that you will like, kill him if he says anything. And he's been cheating on you with practically everyone we know, for like 2 years. Oh crap, I didn't mean to tell you any of that. I just had mouth diarrhea.