Little Pablo wanders into the kitchen where Mama is making some tortillas. He takes some of the flour, smears it on his face and says "Look Mama, I'm white!"
Mama whirls around, slaps him in the face and says "Go show your Grandfather!"
Little Pablo, confused, goes into the backyard where Grandpa is tending the garden and says "Look Grandfather, I'm white!"
Grandpa gets up, takes one look and nails him right in the butt with a shovel. Then he tells Pablo to go show his father.
By this time Little Pablo has lost all enthusiasm but goes back into the house just as Papa is coming in from work. "Look Papa, I'm (he winces) white."
Papa, tired from working 2 jobs, puts down his lunch pail, bends Little Pablo over his knee and delivers him a serious ass-whipping. When he's done he tells Pablo to go into the kitchen and wipe that flour off.
When he gets into the kitchen Mama asks him, "Well, did you learn anything?"
Little Pablo says, "Yes Mama, I've only been white for 5 minutes and I already hate all you fucking Mexicans."