A suggestively named fictional sexual position, referenced (often as a joke) in a TV show or movie, which then takes on a life of its own, and is created. A previously successful example is the Venus Butterfly; an unsuccessful example is the Guatemalan Face-hat.
Just put a name, place, or nationality together with any other noun, call it a sexual position, and people will either claim to have done it, or will invent it - Mexican Halloween all over again
A Mexican Halloween is a sexual act. It occurs when a man is having sex with a woman from behind and upon ejaculation, he opens up a can of chili con carne he had hidden earlier, and throws the contents of the can onto the woman's back.
Note: The chili con carne can sometimes be replaced with salsa sauce.
Another name for the (fairly uncomfortable) Bermuda Triangle sexual position, so called because the triangle between the woman's arms, her back, and the man's stomach resembles a chip.
A bunch of people saw Community and decided to invent Mexican Halloween online, not realizing that Mexican Halloween is not a sexual act, but a sexual position.
A sexual position in which the man is taking the woman from behind, aka doggie style, while he is wearing a sombrero, she is wearing the Mexican flag tied around her neck and he’s holding like reigns, and he is screaming “¡Andalé!” and she is screaming “¡Bueño!”.
Him with his boys next day at school: “Damn, my back hurts so bad. I Mexican Halloweened my girlfriend real good last night.”
The act of dipping your cock and balls in caramel and then having your girlfriend lick it off wearing a Lucha mask.
I asked my woman if she wanted to bob for apples last night. She one-upped me by adding caramel and a Lucha mask. Turns out it was a Mexican Halloween!