You know, this thread always reminds me of various humorous situations that other people have come up with (up till now it's been xkcd comics), like right now I'm reminded of that Seinfeld episode where Elaine runs out of toilet paper and asks the person in the stall next to her to pass her some.
Alright, I'll try to think of some myself...
"I thought I told you to come alone"
"How much do you usually charge?"