my favorite thing to do is when using the usual mannerisms that just keep conversation flowing is to just never finish the full back and forth on em.
"well, you know what they say."
is especially fun to leave at a full stop because if they ask for you to expound you can just put a confused and concerned look on and go "I...I thought you knew...."
do you either twist it into full blown ignorance of not knowing what they say and assuming the other person did? perhaps you go for the "ive said too much" route and bring it to a standstill as you hold a secret that doesn't exist. the world is your oyster, many doors yes.
