Green’s Dictionary of Slang

fiasco n.

[joc. mispron.]

a fiancé; occas. fiancée.

[Aus]Bulletin (Sydney) 26 Jul. 14/4: Two ex-mummers and their elderly hubbies, another ex-mummer and her ‘fiasco,’ and a racing magnate’s wife brought down the glasses of galleries and circle on their respective heads.