Dunno if this one is still going.... but

My mother and father used the expression "black over Will's mother's" a heck of a lot in the 1950s/60s. They were born and bred (!) in Peterborough (originally Northamptonshire, then Cambridgeshire, now it's own county - the "Soke of Peterborough". Unrelated - maybe - I don't think my father actually knew my mother's name - she was always known as "duck"....