I'm a huge fan of old etiquette books and Miss Manners' Guide to Excruciatingly Correct Behavior has to be my favourite. Here is a quote from her chapter on Modern Romance. Keep in mind that I have a 1982 edition.
"There are three possible parts to a date, of which at least two must be offered: entertainment, food, and affection. It is customary to begin a series of dates with a great deal of entertainment, a moderate amount of food, and the merest suggestion of affection. As the amount of affection increases, the entertainment can be reduced proportionately. When the affection is the entertainment, we no longer call it dating. Under no circumstances can the food be omitted."
Everyone should model their dating after that description. I also love it because it could probably be written as a nice equation.