What is Mayonnaise N' Mustard?
Simple as dat. Formally used by bay area rapper "Pill Clinton", a.k.a. Mac Dre. To explain a complex situation with a short connotation, such as "thats that".
We hopped over there, mayonnaise n' mustard, yyyyaaaaaddddaaaammmeeaaannnnn??
See mac dre, slang, thizz