Raincheck

Somebody once told me that he was going to have to take a rain check.  I told him that I was rather offended on several accounts, not least of which was because he seemed to think that I would give him a wet check, but also because he had the audacity to expect me to pay him because he had to cancel our meeting to discuss our plans for building an army of mutated, man-eating mushrooms.  Some people are just always looking for a way to scam you.