i know you know
You throw this phrase in when you agree with someone and you want to act like you’re in on the secret. It’s like you’re trying to out-cool them.
Your friend says the movie was trash and you say, 'I know you know.'
You and your friend both hate the same teacher and you say, 'I know you know.'
You and your friend both know the teacher is out to get you and you say, 'I know you know.'