I first heard about this from a well-known David Letterman Top 10 list. Phrases like “Jumping the Turnstyle” or “Tethering the Blimp” which sound like they mean something sexual but actually don’t mean anything.
So, I was behind a family minivan this morning. It had a bumper sticker which read: “We <heart> Back Door Donuts” Okay then.
After Googling it, it seems to be a shop in Massachusetts - but still…
Again - it isn’t sexual/dirty these days - it means “done in by their own scheming” or so. But didn’t Cecil explain that it’s origin has to do with farting? Or perhaps the bomb that is referred to as a petard - which would hoist you if you set it off too early - was nicknamed using the word for fart, petard (like that Fartiste fellow, Le Petomane…)