OP, I'll have you know that I pull that joke every single time it happens. And I make sure to throw out a great, heartfelt laugh and slap my knee just to make sure you get the joke.
I was once cleaning outside and had a customer tell me "You missed a spot!" He then proceeded to laugh his ass off the entire time he was walking away from like it was the funniest joke he ever heard.
I wasn't even mad. If it brings you that much joy you do you man.