My first table on Friday pissed me right the fuck off. They were my only table, so they had my undivided attention; they seemed like a perfectly nice, normal table of three. They said please and thank you; they were polite and ate quickly. We exchanged a little small talk, and basically they'd've been totally unmemorable.
Except their bill was $50 and they didn't leave me one goddamn cent. As I stood looking at the table in disbelief, I saw the three of them getting in to their car right outside the window. I saw them watching me. And I didn't flip them off.