We all know as a matter of indisputable fact not to be questioned by anyone - on pain of death - that our offspring will never, ever have sex.
We know this (the happily delusional tribe of mums and dads of young girls who begin to view the lovely neighbourhood boys as the lone males on the fringe of the pack in some suburban Richard Attenborough moment) like we know the sun will come up and that we were supposed to buy power company shares - because we are, after all just ordinary Kiwi mums and dads.
So when the small person comes home and insists that she needs to have her HPV vaccine that will protect her against a host of cancers as well as genital warts and cervical cancer, which she maturely outlines in a Powerpoint presentation, I nod and smile encouragingly on the outside.
On the inside, I have already gone into the foetal position and am rocking and shaking my head whilst screaming ... Nooooooooooooo! They're all growing up too fast!!! "Perhaps we should wait a few years?" I ask hopefully. "Mmm. I thought you might say that. I've googled 'cervical cancer', it really doesn't sound like fun. Just be sensible and sign the paper.'
I remind myself that in order to maintain my tentative hold on being the adult in the room I should perhaps start acting like one. I stare into space and briefly contemplate joining a Christian fundamentalist sect where this won't be a problem.