What is more useful when it ...

A college student picked up his date at her parents home. He'd scraped together every cent he had to take her to a fancy restaurant. To his dismay, she ordered almost everything expensive on the menu. Appetizers, lobster, champagne. . .the works. Finally he asked her,
"Does your Mother feed you like this at home?"
"No," she said, "but my Mother's not looking to get laid, either."