When you awake to a fellow bending over you in the "toilet position" with his balls in your mouth and a fart escaping out his arse on to your eyes. Popular on stag do's. This was named due to the similarity to the warm Mexican air and salty taste in your mouth.
When a women wakes a man up in the morning to perform oral sex on him while she simultaneously dips two finger in hot sauce and shoves it up his rectum.
When there aren't any whole tortilla chips left and just a bit of salsa left in the bowl, one dumps the remaining chip fragments into the salsa bowl, stirs it up and eats the rest with a spoon.