Abbreviation for "Stay Thirsty My Friends." This tagline is added at the end of every commercial in an advertising campaign by Dos Equis beer. The campaign features "the most interesting man in the world." Played by actor Jonathan Goldsmith, and narrated by Will Lyman, the commercials tell of the exploits and personality of the main character. The claims attributed to this man are funny because they are so ridiculously exaggerated. They play like a Chuck Norris joke, only with more charm. Fans of the campaign have begun making up their own legends about the man, tagging them with STMF.
His mother has a tattoo that reads, "Son." STMF.
He doesn't swim with sharks, sharks swim with him. STMF.