2006: and who could forget his exhibitionism when he stepped out of the sea this week in a pair of swimmers referred to universally as budgie-smugglers. — Daniel Hoare, Australian Broadcasting Commission, The World Today program, 24 November 2006, reporting on the Victorian state election (and see SMH of Baillieu in the garment in question).
Usage. Used only in the plural form, budgie smugglers.