three finger slinger

A large dip in your mouth. Widely used by red necks in Appalachia

I'm gonna put a three finger slinger in and kick your ass

Three finger slinger

Someone uses 3 fingers (index, middle, and thumb) to stroke a small, fat pecker.

I have to go, Steve is waiting on me, and if I’m late he’ll just give himself the three finger slinger and go to bed without me.