Dumbest thing you've ever heard?

[private joker]

I was playing basketball with a group of friends in middle school/high school. Two of them (Nathan and Rueben) were twins -- not identical, but fraternal twins; they looked sort of alike, but you knew they were twin brothers because they were both dumb as a box of rocks.

Also, they didn't like each other. During the game, they got very confrontational and started trash talking each other. As dumb as Nathan was, Rueben was even dumber -- when things got really heated, Nathan made a mean comment about Rueben, and Rueben shot back with the best comeback he could think of: "Oh yeah? Well your mother's a whore!"

The funniest thing about this was the aftermath. The rest of us started giggling to ourselves, and Rueben didn't get it. Nathan goes, "You idiot, she's your mother too!" And Rueben goes, "Oh." And he pretty much shut up after that.