When someone does something sneaky or stupid, then when they are caught say "I thought you knew." aka "I didn't think you needed to know"
Your girlfriend cheats on you with some guy, then weeks later says "I thought you knew"
by Hives! December 9, 2004
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heard in pockets of the southern US: an affirmation; agreement; inferrance of common knowledge... usually accompanied with a hair toss, whether or not there is hair to actually toss... expletives can be added to show emphasis or anger
"Everyone here wants to do you, Angie"
"I thought you knew, honey!"

"Donita knows not to mess wit yo man since you pulled her wig off and smacked her with yo heel!!"
"Thought you muthafuckin-GOTdamn knew!"
by cactus614 April 15, 2005
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when someone who is usually a smart ass asks you a question you reply by saying "i thought you knew"
tere: where is the meeting at?
greg: i thought you knew!!
by balabalabalabal July 25, 2005
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when somebody discovers something shocking about you, this is the perfect thing to say.
roomate: dude did u kiss a dude at that party last night?
me: yeah im bisexual i thought you knew that.

me: *snort* *snort* oh yeah this is the freakin stuff!
roomate: ALLAN are you snorting DRUGS? WTFs WRONG WITH YOU?
me: oh yeah i do cocaine i thought you knew that man.

me: hey dude
roomate: allan you're a sexually confused dope addict i want you OUTTA HERE ASAP!!
me: wtf i thought you understood me!
roomate: hmmm... yeah im a republican i thought you knew that *snicker snicker*!
by Allanator July 11, 2011
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