The act of tongueing the ass of a lover with diarrhea.
She admittedly ate Taco Bell before our date, and as it turned out, I gave her the ol' mustard plug the next morning.
by Joe Dugger May 04, 2005
The crust left on the end of the eurthera after sex that makes pee go in several directions simultaneously.
"She got mad when I missed the toilet, but she calmed down when I told her I had a mustard plug."
by Helpful guy. April 11, 2014
when a man fucks a women with a yeast infection, and then sticks his meat in her ass...and then it burns
johnny gave that nasty ho with a yeast infection a mustard plug
by dominick July 10, 2008
The yellow, green or brown paste found on the end of ones penis after engaging in anal intercourse.
The sex was great last night, except I got a mustard plug.
by Misfit December 18, 2003