What is Mentiroso?
1.
A liar, especially a man. Used in Latino English and Spanglish, from Spanish.
"Get out papí I ain't gon make love to no mentiroso"
"
Maricon te digo que no debes salir con él cuz he a mentiroso" (Bro I am telling you not to go out with him cuz he a -.)
"Mamí no te voy a engañar, crees que I'm a mentiroso or somethin?" (Girl, I'm not going to cheat on you, do you think I'm a liar or something?)
See
2.
to be a liar
Pinche mentiroso! Fuckin liar!