(A customer approaches one of my cashiers holding two children’s t-shirts with identical logos one boys and one girls. We were having a liquidation sale and all boys’ clothing was 40% off while girls’ clothing was 50% off.)

Customer: “What’s the discount on these?”

Cashier: “One is 40% off and the other is 50% off.”

Customer: “Why are they different?”

Cashier: “One is girls and one is boys.”

Customer: “I don’t understand… what’s the difference between girls and boys?”

Cashier: *without even skipping a beat* “Boys have a penis and girls have a vagina.”

(Cue the entire checkout line laughing.)

Related:
Some Questions Should Never Be Asked