I like to pretend I have no idea what a completely ordinary thing is and see if I can trick my wife and/or friends.
Example: hanging out one day and someone mentioned “the birthday song”
Me: the what?
Her: the birthday song
Me: what’s that?
Her: you know, “happy birthday to you.”
Me: I have no idea what you’re talking about.
Her: Happy birthday to you. Happy birthday to you.
Me: (puzzled look). I have no idea what you’re singing. Did you just make that up?
Her: YOU’VE NEVER HEARD THAT SONG?
Me: Don’t think so.
(about this time, I start to feel like I’m being cruel).
My wife is onto me but I can still get her occasionally.