How about - "I promise I'm not a cop!" Lol. I love that one. Because you can always rely on the promises of a stranger.
Or the question of "I don't have enough money right now. What can I get for X amount". Umm, excuse me, do you ask a car dealership for a discount if they take out the radio and disable the power windows. NO! Lol. Its a package deal. Take it or leave it.