Pea Soup
Two missionaries in Africa were apprehended by a tribe of very hostile cannibals who put them in a large pot of water, build a huge fire under it, and left them there. A few minutes later, one of the missionaries started to laugh uncontrollably.
The other missionary was incredulous, and said, "What's wrong with you? We're being boiled alive! They're going to eat us! What could possibly be funny at a time like this?"
The laughing missionary said, "I just peed in their soup!"