What is Fall Through?
1.
Means your plans didn't work out for some reason.
(imagine someone trying to cross one of those suspended wooden bridges and falling through)
"Dude I know you're trying to hook up with that chick tomorrow night, but if that should fall through call me up and we'll play some
vidja games ."
See
2.
to make happen. Succeeding.
He made sure to fall through with getting a party bus.
See