Just starting to be used in
Toronto,
Canada.
It means that you should stop what you're doing or saying
ASAP. It is said from one person to another.
Boy 1: Yo b, I was
looking fresh on friday.
Boy 2:
Park that dawg, no you didn't.
erks has the same meaning, but is only used by girls. Park that, allows guys to put a stop to another's saying/doing.