You know what it's like. You invite the nice folk you think you'd like to impress round for a barbie. You spend slightly more on the prawns than you meant and buy a case of clean skins because you don't want to run out of grog if the evening starts to kick along.
At first it all seems to be going well. The visitors are smiling and nodding in the right places even in some of your more dubious anecdotes. But then the evening starts to drag and you and the missus exchange eye contact a couple of times and realize that on this occasion at least you're both in synch. It's time for them to go. You start dropping hints: you have to get up early in the morning, the kids have been running you off your feet, you're very tired and you even attempt a not so subtle yawn or two. Still they sit there holding out their glasses for more.
Now it's getting serious. Do you state the obvious or continue with the subtleties? At what point exactly do you lose all tact and shout loudly across the lounge room: 'Go home you pair of historical anachronisms swanning around the countryside at the Australian tax payers expense! Liz and Phil, I guess it was kind of nice to catch a glimpse of you and get some sense that as head of state you do remember we actually exist, but now it's time to leave! We've got things to do: carbon and mining taxes to debate while simultaneously selling our children and grandchildren woefully short because we're not taking them as nearly as seriously as we should. But we need to abase ourself in private if you don't mind. Now go home and live off your own taxpayers again!'