When a woman tugs on a man's flaccid penis while urinating. She tugs on it in a fashion so that she is getting sprayed like gasoline coming out of a nozzle.
Guy 1: Gina is such a whore.
Guy 2: Why, did she offer to give you a goldengas pump?
Guy 1: Yeah, and I totally went for it.
Fuck a girl with your cock, hence the pump. Once the vagina is dilated, fart in the orifice. Hence the gas. Michigan, because that's where my last girlfriend was from.
The act of thrusting the gas nozzle in and out of the tank after filling up in order to remove excess gas in the nozzle to prevent dripping onto the side of your car.
Ron: damn it I always spill gas on my car after filling up
Jeremy: you gotta remember to get all the liquid out with a quick gas pump thrust!
starting off with simple tea-bagging, making sure that her nose is between your ass cheeks, and as she is jacking you off, you fart as much as possible.
While pumping gas, you try to release the pump trigger at the number you want it to land on in one try. The less risky people release a few cents underneath the target number then pump the trigger until it gets to the number. It is kind of reverse of russian roulette.