If you’re unfortunate enough to have a waitress who is having a bad night, don’t give her any shit. You never know if she’ll do something devastating, like dipping your hamburger bun in her menstruation blood (extra ketchup, sir?) or even (gasp!) bringing you decaf instead of regular.
We can’t help you too much with that first one other than to advise you to bring a barf bag, but as for something as important as your coffee, there are D+Caf strips, which allow you to test your coffee to see if your waitress brought you what you asked for. A set of 20 costs $9.95. So, that’s with two cups a sitting, that’s at least 10 safe sittings.