1.  He plays culturally appropriate games.
At our house at least once a week the boys play “piñata”.  They fill a bowl with “candy” (usually the alphabet magnets from the fridge), get something to use as a stick (a wooden dowel from their train set will do) and make me chant the Mexican piñata song while they take turns hitting the bowl until the “candy” falls out.

2.  He translates important words for you.
While sitting on the toilet, yesterday Eli carefully informed us, in his best Mexican accent, “En Español es poo poo, you say poo poo”.

3. He recognizes the finer parts of American households that are often missing from their Mexican counterparts.
You would not believe how excited this kid is that the new apartment we are moving into has a bath tub.  While touring a different apartment, which also had a bath tub, he came out of the bathroom shouting “But where are all the bath toys?”.