My father told me this tale some years ago; he said he heard it from a colleague from work, and it might or might not have been a true story. A young couple had a problem: they had invited another couple over for dinner once or twice, and had since been plagued by regular visits from their friends just before dinnertime. Wanting to be seen as polite hosts, they had invited their uninvited guests to stay for dinner time and time again, but had gradually begun dropping subtle hints that the friends might wait for an invitation before stopping by again at such an inconvenient time. Their friends, however, either too dense or too rude to get the hint, persisted. Finally, they came up with a plan to get rid of them once and for all. The next time their unwanted guests dropped by, once dinner was over, the couple put their plates on the floor next to the table, and called for their pet golden retriever to come and enjoy the scraps; their friends followed suit. As goldens are always hungry and love table scraps, the plates were rapidly licked clean. The husband stacked the plates carefully, and carried them into the kitchen, where he casually put them back into the cupboard, in full view of the shocked guests. The silverware followed suit, and the couple offered their friends desert and coffee, but, looking a little green, their guests declined, protesting committments at home or some such. Once their guests had left, the couple (laughing hysterically to themselves) washed the dishes properly, but that was the last time their friends appeared at dinner uninvited.
(From the "Rest" of RHF)