Given that I’ve cleared my conscience, I feel that I can offer some advice on how to torment people you are going to dinner with when it comes to the paying of gratuities.
Scenario the First:
It’s been a really good dinner. Both of you are paying for yourselves. The other person leaves a hefty tip. What you do is not only to not give any gratuity, but indeed to pay under what you actually should, so that their generous gratuity is completely nullified or, even better, reduced it to an insulting amount. If they do not notice this, let them know as soon as you have left the restaurant.
Scenario the Second:
It’s been a really good dinner. Both of you are paying for yourselves. The other person leaves a hefty tip. You say “Oh, that’s far too much of a tip”, take most of the tip-money from the tray, and put it back into your wallet.