Depends on the granny, cnd; in our family, we used to refer to "mother's driving words" for untoward expressions used while holding the steering wheel, but it's not just us. One of the contributors at the Lake Sessions read a rude poem about swearing, which included unexpurgated examples; afterwards, she apologised to the MC for doing so in the hearing of the MC's early-teens son, who was sitting in the front row. Said son replied that he'd heard it all before and worse from his mother.

I wish I could find where "Freedom of speech is never so valuable as when a man hits his thumb with a hammer" came from ....