1) to jerk off in a soda can that just happens to be nearby
2) to jerk off with a full soda bottle inserted into the rectum
The old style coke bottle works best for a soda jerk. It fits good, is ribbed, doesn't need any lube, and the caffeine enema keeps you coming...
A person who works at a soda fountian.
I just got a job as a soda jerk!