I'm going to snap at a prying question
What did this person do that was prying?
The keep asking questions without an ending, just to talk to someone.
This person may just be lonely or looking to distract them self from some sort of other problem.  You should do your best to be patient and understanding with annoying people. I'm sure they will appreciate it!
I know that. I'll just walk away, after I'm done being mad.
The kindest thing to do is to be a little patient if you can manage it. It sounds like they're just lonely. If they're really prying, feel free to move along, but you don't need to snap at them.