Green’s Dictionary of Slang

washing n.¹

SE in slang uses

In phrases

don’t hang dirty washing in my backyard

(US black) don’t lie to me; don’t tell me stories.

1942

Z.N. Hurston ‘Story in Harlem Sl.’ in Novels and Stories (1995) 1002: Gar, don’t hang out dat dirty washing in my back yard!