Fill Tank 

When you nut inside your partner without a dome.

Alex B: Yo, do you have any domers?
Mike P: Nah, just fill tank man.

Fill Tank by Union St November 8, 2017

Fill Tank 

When you are having raw sex with a broad and you proceed to pee while you are balls deep in her vagina.

Yo I might fill tank tonight at Bella’s dorm after slamming these beers.

Fill Tank by gamblerontilt August 28, 2022

fill the tank

To shit in the back tank of a toilet, after removing the cover. This is best done in a public bathroom, as the turd(s) will not likely be found for several weeks, despite the pure, rancid stank it will emit. Due to the general orientation of the toilet tank and the wall, this can be a difficult task, and any successful attempt should be properly commended.

Stephon: Any needledick can shit on the floor at Wendy's; it takes skill and grace to fill the tank.

Crew: roflberry pwncakes

fill the tank by J Hate June 1, 2006

Gas tank fill-up

The art of having anal sex with a female, and while she isn’t looking you pee in her butthole to save you a trip to the bathroom.

Chad: Dude my girlfriend broke up with me because she was shitting piss for days after I gave her the good ol’ Gas tank fill-up

Gas tank fill-up by Longballe_d October 9, 2018

Fill The Tank

when you blow a load in a girls mouth, much like filling the gas tank on your car.

i sure filled her tank

Fill The Tank by Kyle December 25, 2003

fill the tank

To shit in the back tank of the toilet after removing the cover. This is best done in a public bathroom as it may not be discovered for weeks, despite the pure, rancid stank it will emit. Due to the orientation of the toilet to the wall, this task is often difficult, and any successful attempt should be properly commended.

Stephon: Any needledick can shit on the floor; it takes skill and grace to fill the tank.
Crew: roflberry pwncakes

fill the tank by J Hate May 30, 2006

Fill Up Your Tank 

To pregame or drink before you begin your night out on the town. To consume alcoholic drinks at one's home, perhaps due to: a rough economy with hard times, being an underage child without a fake ID, or in most cases, insurance for good times.

Me: "We're going to a speed dating event tonight???"
John: "Yep at 10pm"
Me: "Wanna come over and fill up your tank at 8?! I'm gonna need it!"

Fill Up Your Tank by Stephanie Cooper February 11, 2009