To worry about inbreeding?

[DancesinPuddles]

So, my SIL and her wife have a lovely daughter. She was conceived using sperm they obtained from an enterprising young man on the internet who is paying his way through university by selling his 'product'. Not the way I would go about it but hey ho, each to their own.
However, during a recent conversation I discovered that he has now fathered at least 23 children. AIBU to find this a bit worrying? No one else in my family seems to think so. I did raise the question of how they would ensure the siblings didn't meet and breed - apparently they are all going to have a list of their half siblings to refer to. Am I crazy? I feel like I've entered a parallel universe during these conversations!

The donor sounds like an idiot, is there no way to stop him?

I have a lovely friend who had a bit of a mad family dynamic. When we were teenagers she kissed a boy who she later found out was her half brother. It was devastating for her and it was only a wee snog.
What got her most was this was someone she had looked at sexually and he was the same relation to her as the brother she had grown up with.

yabu yet yanbu.

Not always clear cut, eh?

I suppose it has always been the case that a certain percentage of children are not related biologically to the man they think of as being their father- that's just a matter of fact.

Are societal changes making this worse, though? Oh yes, definitely.

While the nuclear family model is not perfect (people have affairs, obviously!), it is, generally speaking, a good model to avoid inbreeding (sorry, but I'm not that hung up about that word) blended families and the like surely make the potential for people having sex with half-siblings more likely to occur.

Sorry if this gives offence, but that's the truth of the matter.

People dismiss the nuclear family as old hat and, like I said, it doesn't always prevent people having sex with half-siblings, but at least in principle it was a way of avoiding people having unknowing sex with close relatives.

I would do it if I knew of any reason why I should (the type of things talked about on this thread)

'DD1 doesn't know her father' was a quote from LEM at 18.14 02. Missed the quote marks off.