mexicanfoodporn:

Mexicanfoodporn and the Spanish lesson of the day
“Vamos a pistear” = “Lets drink” (booze) 
People make the generalization of thinking all spanish speaking countries have the same words, however these vary even in the same country.
Pistear is used widely in Northern Mexico to say “Drink”, you might not hear this word in southern or central mexico though, they usually use “Chupar”.