1) To pretend a conversation has reached its end, a subtle (or not) attempt to cut off what the other person is saying and conclude matters immediately.
2) A disconnect in conversation wrought by distraction.
Lora: "So then my uncle calls me back and starts telling me all about his . . .
Jeff: "Well, that's great, so I guess I'll talk to you again really soon."
Lora: "Don't you short-talk me."