I won't ask him if he knows about the well-digger's ass

I was coming downstairs to fetch a fresh brew to inspire me to do the dishes. Housemate The Croin was deep into the Justice League video game. "Did you bring the brass monkey in, or should I?" I asked given that it was 10 degrees out and it was only 6:30 in the evening.
"What?"
"Did you bring the brass monkey in or should I?"
"Brass monkey?"
"You don't know about the brass monkey?"
"As in brass monkey, you funky monkey?"
"No. Brass monkey as in freeze the balls off a. As in it's cold enough to freeze the balls off a brass monkey. It's ten degrees out, dude!"
"Sorry, I've never heard of that expression."
"What the hell are they teaching kids in school these days?"