I dont know if somebody here have got it right yet, but I
believe that "ese" means, okay, first
literally: That thing. As in "that thing you've got down there." So figurativelly is a bad word; it means: Asshole. I hate it when someone, typically a stranger, call me "ese." It's usually only spoken by the lowest educated and bad mannered Mexicans,
Mexican-americans, hispanics. For example: hispanic gangs, etc.