When you nut inside your partner without a dome.

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.

The act of expelling urine into a woman's asshole. Often brought about when asking "May I pee in your butt?".

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

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.

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

Peeing in a girls butt during anal.