Put That Rhodes Scholarship on Hold

The boy will learn manners. "Thank you" will never get old. You will not direct; you will ask, and say please. Asking him what the 'magic word' is doesn't work, because he just says 'magic word' back to you. If he demands something, usually a raised eyebrow and stare will illicit a "May-I-Please!" Usually.
But tonight he was out of water, and struggling to put his cup on the counter.
"Is it empty?"
"Yes."
"Would you like some more?"
"Yes."
"Yes, what?"
...
"Ryan, what comes after 'yes'?"
"Five!"