White people love Cinco de Mayo because it combines several of their favorite things: multiculturalism, diversity, nachos, being an expert on other cultures and binge drinking. However, Cinco de Mayo is a potential minefield when it comes to offending white people, which they love. But when they're drinking, it can get messy.
For example, telling a white person that Cinco de Mayo actually celebrates Mexico's victory over the French in the Battle of Puebla in 1862 will most likely result in blank, slightly hostile stares, because white people hate to be corrected.
Therefore, when hanging out with a white person on Cinco de Mayo, it's best to ignore this fact and simply buy them a Corona, a shot of tequila or a frozen Margarita, the official white-person drinks of Cinco de Mayo. White people will appreciate both the free drink and the fact that you're celebrating Mexico's freedom from Spain with them.
If you do bring it up and upset a white person, you can correct the situation by telling them you only learned that fact because of your foreign study program in Mexico. This then gives them an opportunity to tell you about their foreign study program, thus alleviating any further tension because they will have forgotten all about you as they reminisce about the price of beer in Prague.At no point should you draw attention to the actual Mexicans bringing the white person the nachos and clearing away the empty Corona bottles. White people become uncomfortable when they think about poor immigrants doing menial labor for them. However, take heart. The more tequila a white person drinks on Cinco de Mayo the more likely they are to begin over-tipping, which will help alleviate the guilt they feel over NAFTA.