what's going down
This means "what is up?" at that moment of time. It has a similar meaning as "what's happening?"
"Oh what's going down cracker"
"Not much slave"
"you call me a slave honkey? I'ma bitch slap yo ass"
"Not much slave"
"you call me a slave honkey? I'ma bitch slap yo ass"
what go down
What's up? Basically.
What go down for tonight G?