The Rubber.
The Connie: Sammy! Can I borrow a rubber?
Son-in-Law: What!?
The Connie: Sammy!! I need a rubber. Just the tip!
Son-in-Law: [whispering to Daughter] What the hell is she talking about!?
The Connie: Dude, I just need the tip of a rubber!
[The Connie refers to pencil erasers as rubbers, but Son-in-Law didn’t know that]