Don't be mamus is a derivation of the Spanish Expression "No Mames" or the softer version "No Manches" This expression is widely used in
Oaxaca de Juárez, Mexico to indicate that someone is taking advantage of you in some
way. It can also portray the sense that someone is exagerating some point. It also can be used to
mean "really?" or "you don't say" Additionally it has been used to express an informal greeeting such as "hey" or "what's up?" or in departing a "goodbye".
Someone taking advantage of you. "They charged me fifty dollars for the repairs" Response: "Don't be mamus"
Greeting...said as one approaches
friends: "Don't be mamus"
Goodbye...as one leaves the presence of
friends "Don't be mamus"
Surprise..."I won the lottery" Response "Don't be mamus!"