Mental Impurities

(I am talking to a customer about various options for earrings.)

Customer: “Can I see your 25 carat gold earrings?”

(I go and fetch the earrings from the back.)

Customer: “These are definitely made of gold? There’s no nickel in them?”

Me: “No, there’s no nickel. Are you allergic?”

Customer: “No, I just don’t want to get HIV.”