Take it from Sara Blakely, founder of Spanx.

You don’t want to be live on-air in Britain and make that rookie mistake of calling your fanny your bottom. Even if you think “fanny” sounds like a Britishism – beware. It’s not. They don’t call fanny packs “fanny packs.” You’ll be hard-pressed to find any British natives named Fanny, not even in elderly care facilities. They don’t even use the grammar rule “Please excuse my dear Aunt Fanny.”

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