Based on the rule that states:
If it looks like a duck, waddles like a duck, and quacks; it's a duck.

Used in real life to explain the obvious truth of the matter.
Dude 1: Andi was sure cranky when I asked her about last night at the bar. She was going with her girlfriends.
Dude 2: Is that all you asked?
Dude 1: Yeh, but when she got home her shirt was inside out, she smelled like cologne and her back is scratched up. I had to ask.
Dude 2: No you didn't. Rule of Duck. Andi is a whore.
by abrasive personality August 14, 2011
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