A members comment just reminded me. A local gift shop sells door signs, to pin up by your door bell. My favourite reads. "Oh no, not you again."
Oh man oh man, I need a sign like that for my door! Unfortunately I would not have the guts to post it. It would be meant for one particular person, and she'd know it! Haha!
Of course she would. But perhaps it would be indirect and ambiguous enough that you could get away with it. LOL