Fill the gas tank

To urinate in a sexual partner's anus.

Person A: I went home with that girl last night.

Person B: Did you "fill the gas tank"?

by tabittle August 6, 2009

Filling The Gas Tank

Filling the gas tank is when you stick your dick into someone's ass (male or female) and proceed to piss.

Cade: I got laid last night.
Owen: Yeah right, by who?
Cade: Bronwynn let me try Filling the gas tank
Owen: 🅱oi

by Loaf of Beans June 15, 2018