Luckily, merely putting unleaded in the tank of a diesel car ain’t so bad – as long as don’t start the engine and pump it all through. Still expensive though: We got the car towed up the street and the tank dumped out and refilled.

That sentence is very poorly worded, I think, and I probably should have used “required” rather than “encouraged”. What I was trying to say was basically this: legally speaking, it is exceptionally difficult to not have a mandated relationship with your parents-assigned-in-infancy[1] at least while you are a minor. If you have children you also have a legal relationship with them that’s not easy to set aside (and as per footnote [1], it’s harder to set aside in Australia) but there isn’t legal coercion to have children in the same way that there is legal coercion for a minor to have parents. (There’s considerable societal coercion to have children, but it’s not mandated by law to reproduce[2] as the fact of having parents is.)

[1] That wording chosen to try and account for several other parenting arrangements assigned by law that don’t involve the genetic-mother-and-father-assigned-as-parents arrangement. Although in Australia infant adoption is now exceptionally difficult and rare, so you could almost use parents-assigned-at-birth, here.

[2] At least, before one happens to be pregnant, then it varies between jurisdictions.

I’m not sure I understand your assertion that [a biological child is] “not the family the law encourages you to have.” Or am I misreading that?

I have two speed dials set up. One is to Jeremy, the other is to the wife. But I ring my parents on Sunday.