You know, it's pretty easy to tell when you are being played for a tip, there are some unique tell-tale signs.
1) Wife is ignored while husband will be referred to as honey, dear, sweetie or some other term of endearment.
2) The waitress gives you extra portions that you are never charged for.
3) Ahhh, the gentle touch of the hand to a shoulder.
4) And of course the one that we are discussing here, "Do you need change?" This is my particular favorite that I handle one of two ways...
1) Heck yes dear, give me my chane...my wife will take care of the tip! This works extremely well if you are in the company of your wife or other female...doesn't work with a group of guys or if you are dining alone.
2) If you are dining alone and asked "Do you need change," a good reply is "do you need a tip?" The shock will leave her flabargasted for a few seconds while you sort your coins and leave the correct tip.
BUT on the other side of this discussion, we have a family that comes into our restaurant, we affectionaly refer to them as the Adams Family. It's a mother and two teenage sons, the mother is fry short of an order and the two sons think they are God's gift to everyone one of our waitresses, doesn't matter if they are 16 or 61. While they are here they will run a waitress to death, constant refills, extra salad dressings, more this and that and expect to be entertained by the waitress at all times. I really have done my best to run them off, but they keep coming back like a bad dream. They'll easily run up a bill of $20 to $30...and never, never once has a tip been left.