You know when u put a quarter in a gumball machine and u just watch the gum come down twirlin downwards....

It's like when a dick all in your guts all the way in there making the cum trickle downward on the dick

referencing Gumball 3000, this means to drive aggressively and greatly exceeding the speed limit, usually for fun or to make a getaway.

Gum-ballin' is the act of placing ones testicles in someone's mouth who lacks teeth.

Not to be mistaken for tea-bagging, but generally the same idea, just... well... the sense of danger is less because there are no teeth involved.