Discount Or Dismount?

(An older man comes up to the counter where I am currently ringing. On either side of me are the other two shift managers; both are distracted by work-related things, leaving me alone to ring. The man has with him an older engineering book that is rather high in price.)

Customer: “Is there any discount on this?”

Me: “We don’t have any discounts right now, but let me see if I can knock off a few bucks for you.”

(While I’m looking at the date, we price the book and the condition, the man bemoans about how old it is, and that it’s too high, and that there’s a small tear on page whatever, essentially trying his best to find a discount by any means necessary. Just as I decide to give him 10%, he comes out with this gem.)

Customer: “What if I let you ride me like a horse?”

Me: *stares at him in alarm for a good ten seconds before firmly saying* “SIR. That is not appropriate whatsoever to say to me. I don’t want you saying anything like that to my staff here, either. Now then, you’ll be taking this book today, right?”

Customer: *stutters* “I… Well, yes, I am sor—”

Me: “GREAT.” *scans book* “That’ll be [total]! Credit or cash today, sir?”

Customer: “Cash, um, yeah, I only meant—”

Me: “Awesome. Do you need a bag today, sir?”

Customer: *gets the hint and nods, giving me the cash and eventually leaving*

Other Two Managers: “DID THAT JUST HAPPEN?!”