We are widely instructed not to visit the sins of the father upon the son, and, largely, most of us manage to obey that stricture.

But how about the other way round, when the “sins” of the son reflect badly on the father or mother?

I had cause to think about that this week when looking at the mess in which the Netanyahu family of Balfour Street, Jerusalem, has embroiled itself.

Item: mother, Sara; occupation, wife to prime minister, almost certainly about to be indicted for alleged corruption.

Item: father, Benjamin, prime minister; corruption charges against him hovering down the track.

And then there is Baby Bear, aka Yair Netanyahu. Honestly, words almost fail when it comes to Yair, because where do we start?

He’s 26, he lives at home, he has no job. And he has spent most of his time over the past month or so, under the “alias” of “Yair Hun” (Attila or Honey?) railing on social media against perceived slights on his family to the point where he has been “embraced” by none other than the far-right anti-Semite, David Duke.

Something to be proud of there, Yair, huh?

So what exactly did Yair say and do when lashing out at his enemies? Well, he posted on Facebook a cartoon featuring George Soros, the Hungarian-born Jewish left-wing financier, a reptile, and a highly controversial stylised “anti-Semitic” merchant. You pretty much know you have strayed into dodgy territory when the cartoon gets endorsed by the Ku Klux Klan and the Daily Stormer, and when the Anti-Defamation League calls the cartoon anti-Semitic.

Then Yair decided to have a go at Israel’s most decorated soldier, the former prime minister Ehud Barak, calling him a drunk who is in need of geriatric treatment.

Again, nice, respectful behaviour. Not.

He took the cartoon down eventually, after four days of febrile headlines in the Israeli press, unusually across the political spectrum. Even right-wingers found Yair’s actions difficult to defend. Although one right-wing friend wondered why I was so offended by Yair – “he’s not running for political office, he doesn’t represent anyone” – both of which are true.

But it is precisely because those things are the case that I pray for Yair – who, let us not forget, has a state-funded driver and security guard – to shut up and show a little seichel. His younger brother, Avner, has managed perfectly well without showing up in the public prints every five minutes.

It remains an unpalatable truth that many people in the public eye have difficult relatives from whom they would rather not hear. Bill Clinton’s brother Roger was a cocaine addict; Jimmy Carter’s brother Billy once pee-ed on an airport runway in full view of a slew of visiting dignitaries; Randolph Churchill appeared to have spent much of his entire adult life drinking, to shake off the legacy of Winston.

But just as there are examples of embarrassing relations, there are numerous blameless individuals of whom we never hear because they are not their brother or sister’s keeper.

I would be thrilled if I never read another word about Netanyahu Jr, but admit it is unlikely. Nevertheless, even at 26 it is not too late for him to reform. Perhaps he could get an intern job in Ehud Barak’s office, and learn something?