Said in place of "fuck" for a variety of reasons. These include, but are not expressly limited to: Amusement, inside speak, put-downs, observation, and generalized phobia of using cuss words. See also: kerpiddilyphumphsk
When you are making nookie with a particularly large person and find within his/her rolls of fat an Item of food which has been stored for a indefinite amount of time ... and consume it or feed it to him/her.
Phumpkin Receiving Man (reading from J. S. Mill's "Utilitarianism"): On a question of which is the best worth having of two pleasures, the judgement of those who are qualified by knowledge of both must be admitted as final.