I'm not sure how I'd react if I got a bill for activities at a birthday party one of my children didn't attend.
Would I throw it in the bin or would I burn it? Hard to call.
But when Britain's Alex Nash, 5, decided at the last minute not to go to a party organised by Julie Lawrence at Plymouth ski slope, Julie sent his parents a bill for 15.95 ($31).
It was disputed. After all, you're not allowed to spend other people's money without asking unless you're a cabinet minister or a finance company.
The mums duked it out on Facebook with impressive vigour. In five Facebook posts Tanya went from "I do not like fighting with people and would prefer to settle this amicably" to "Just so you know, small claims court cost 60 just to start a claim".
It's easy to sneer at people who prefer to communicate on social media rather than in human form, but in this case it may have been the right thing.
It sounds as though Alex's dad's visit to Julie to discuss the matter, complete with doorstep invoice-waving, was confrontational at best.
Nevertheless, it's hard to see the advantage to anyone in conducting this in front of an audience of millions. The only conceivable reason is each person's hope that they will gain the moral high ground and shame the other - a strategy that only ends up shaming both.
So much is wrong with modern child-rearing, and modern children's birthday parties in this case.
Today's parties are about the parents' status, not the child's celebration.
The birthday party of chips, cheerios and pass the parcel is a thing of the past.
The organiser of today's event is faced with numerous culinary and other dilemmas: should you provide some artificially coloured and flavoured food for those who prefer it?
Clown or interpretive dancer? Hummus or dukkah? Katy Perry or Taylor Swift? Julie opted for a party "including snow tubing and tobogganing and lunch" - relatively unpretentious as contemporary juvenile bacchanals go.
The matter of cost appears to have arisen only after Alex decided to skip the party at the eleventh hour when his grandparents announced this was the only time they could make their Christmas visit.
In other words, Alex chose to stay home and get a present rather than go out and give one. Perfectly natural. Alex is a child. We probably need reminding of this about now.
It's also a good point at which to ask what sort of example the parents are setting the children at the centre of this brouhaha.
Do they realise they are using their children to establish dominance?
And that they are falling into the trap of making a personal issue a financial one? And that their children have a right not to be involved in their feud? In short, that they have a right to be children, unencumbered by their parents' expectations and sense of entitlement.
Long summer drives inevitably bring us face to face with misplaced apostrophes on roadside signs. One of the most common misuses is "it's" instead of "its" and vice versa, an error that I happen to know drives many people to distraction. They're probably not aware the apostrophe is a recent innovation - Shakespeare got by without it - and is currently on its way out. But until then, here's a way to get that one right that even Auckland transport authorities could follow. Ask yourself: Is what I'm saying short for "it is"? Then you write "it's". In all other cases, you write "its". Couldn't be simpler.