Butt Mustard

Another way to describe the shit that comes out of a baby, it gets it's name from the color and consistency

You have to change little Johnny this time, I had to deal with his butt mustard last time!

by Metallicajunkie October 4, 2018

Butt Mustard

The watery sound ketchup/mustard makes when squeezed from a bottle.

Wow, Mike, that really sounded like a fart. No, dude, it was butt mustard. I was putting ketchup on my burger.

by Annie Farkle September 9, 2009