When a man, gay or otherwise, has anal sex with at least 3 or 4 other men throughout the same day and night. Girls can be count as part of the mud run, but the one making the run is always a guy.
Guy 1: You guys wanna come over this weekend for a BBQ, some drinks and then maybe a mud run.
Guy 2: Ah, yeah, that could be fun. I've never done a mud run before.
Guy 1: You don't know what you're missing. You can even bring a couple of girls along, just not too many.
Guy 2: Ah, yeah, that could be fun. I've never done a mud run before.
Guy 1: You don't know what you're missing. You can even bring a couple of girls along, just not too many.
by small mammal May 13, 2013

The walk of shame through a camping ground to empty your mud luggage (see definition) in the dump point.
Faye: Hey Ken?
Ken: Yes Faye?
Faye: The caravan toilet is full, you need to do a mud run.
Ken: Fuck!!
Ken: Yes Faye?
Faye: The caravan toilet is full, you need to do a mud run.
Ken: Fuck!!
by Hastos January 20, 2021

by sarge2u June 20, 2008

When a person is taking a dump and a second person sits on the first person's lap effectively taking a dump between person number one's legs.
by skufd January 16, 2008

When there isn't any toilet paper in the restroom you've just pooped in, and you have to make a dash with poop on your asshole to another one.
Corissa: Why are you out of breath, and, by Jove, what is that smell?!
Kevin: Sorry babe, I'm on a Mud Run.
Kevin: Sorry babe, I'm on a Mud Run.
by TheRipper19496 June 25, 2015

The sexual of defecating on your partners back and then using the feces to shape their hair into a Mohawk.
by Thedangler602 August 09, 2022

People you've been through the mud with, aka friends, could be more reliable or better companions than family.
by Victor Torres from Cutler Bay November 27, 2024
