A college student got a job on the railways as a steward one summer, and the first day he accompanied another steward to learn the ropes.
"It's very simple," said his tutor, "just use diplomacy."
"What's diplomacy?" asked the student, as that was something never discussed in his classes.
"Watch me, I'll show you," said the steward-in-charge.
Off they went down the train corridor, rattling compartment doors, opening them with special keys and offering tea or coffee.
When the tutor steward flung open one door, he was confronted with a naked woman. Without batting an eyelid he asked, "Tea or coffee, sir?"
The surprised woman took the cup of tea and he shut the door.
"Wow, did you see that cutie?" said the student excitedly. "She had no clothes on! But hey, why did you call her 'sir'?"
"That's diplomacy! I did not want to embarrass her," said his tutor.
The student was most impressed with his teacher.
The next day, on his own now, he flung open a door to a compartment and found a couple making love on the bed.
"Tea or coffee, sir?"
"Tea," the man replied.
"And for your brother?"