Isn't it ironic?
Irony in this tale is very prominent. There are not many things that happen as they would be expected to. The fart, the personality of the friar, and the teachings of the friar are all great ironies. They are all examples of situational irony. Irony is what drives the humor of this tale. Irony is important to this tale because it helps to aid with the other themes that are in play, Revenge and Satire.