To place an ice cube into a vagina. This term is derived from the Spanish "muy mal," meaning very bad. However, while experiencing a mooey mao, actually exclaiming said phrase is made more difficult by the now icy vagina.
A physical attack on a person involving the assailant presoaking a finger in his\her own anal sweat, then wiping said finger across the victims top lip.
The anal sweat deposited on the victims top lip can be notoriously difficult to remove, requiring vigorous scubbing with a tool such as a pumice stone or a nail brush. Plus the fact that the odour omitted is in such close proximity to the victims nostrils, a mooey moustache attack can be intense and prolonged.