mud-tracking 

When you fuck a girl, or man, in the anus, take out your poo covered dick, and wipe it down her spine, leaving a brown line.

Hey, tell your mom to eat more meat and less vegatables. I was mud-tracking her the other day and the shit on her back was green.

mud-tracking by LuchadorMann December 16, 2006

Mudtrucking

The act where one shits onto one's hand and then uses said hand to masturbate themselves or a third party.

Darren: What's that smell?
Michael: I think Ben is mudtrucking in his room

Mudtrucking by ghost64 November 9, 2014