The phrase dates back to at least World War II, when homosexual acts were illegal in the United States. Stating that, or asking if, someone was a "friend of Dorothy" was a euphemism used for discussing sexual orientation without others knowing its meaning.
.: 100% Airlume combed and ring-spun cotton (fiber content may vary for different colors)
.: Extra Light fabric (3.8 oz/yd² (110 g/m²))
.: Retail fit
.: Sewn in label
.: Runs true to size