What do your mom and a brick have in common? Both get laid by Mexicans.
Are you trying to say something negative about Mexicans with a joke like that?
Well, Mexicans have a hard time getting a job because all these companies give the jobs to niggers.
Telling jokes like that about Mexicans is based on a racist stereotype and implies they are only capable of doing physical labor. That's not true at all and Mexicans are able to and do work in all different kinds of professions. You should be more sensitive to what other races deal with on a daily basis and try to be more sympathetic.