There's an old saying that something is "about as welcome as a bacon sandwich at a Barmitzvah". It's probably not the correct metaphor to describe Barack Obama's feelings about Bibi's presence in Congress today, but it will do.
Just as negotiations with Iran are at their most delicate stage, in comes Bibi to say the deal stinks. If you're the president, that just doesn't feel very kosher, so to speak.
After all, something quite extraordinary did unfold today. The Speaker of the House invited the Israeli prime minister to address Congress and rubbish the president's foreign policy negotiations - without ever telling the White House or the State Department that the invitation had been extended.
We'll come to the substance in a moment - but let's just do the theatre.
Benjamin Netanyahu rocked the Capitol. His political stagecraft was unbelievable. He had them cheering, whooping and hollering. And that was before he'd said a word.
He knew every button to press.
It was said of the charismatic British Conservative politician, Michael Heseltine, that he knew like no other how to find his party's G-spot - well, another more anatomical word was used, but let's not dwell on that.
Bibi does the same in Congress, to the Republican section of the audience at least, and some Democrats - though many stayed away
It is hard to think of any other national assembly - including Israel - where Mr Netanyahu would be given such adulation.
For a moment, I tried to imagine Bibi in the Westminster Parliament, or the Assemblee Nationale in Paris or the Bundestag in Berlin. He wouldn't have got anything like that reception.
But here in Washington his script lines, his delivery and his message had US congressmen and women leaping up from their seats like jack-in-the-boxes.
The argument was familiar, and delivered with great passion and sincerity.
Netanyahu said that Israel faces an existential threat from Iran - and he is convinced that the deal under discussion, far from preventing Tehran to obtain the bomb, will pave the way to that.
He said it was a lousy deal and should be rejected. He argued that there was an agreement to be had, but it depended on Iran stopping its interference in neighbouring countries, it had to stop sponsoring terrorism around the world, and stop threatening to annihilate Israel.
And ultimately, he said, the US was being naive in trusting Iran, whom he argued was fundamentally untrustworthy.
But there was a passage early on in his address which seemed a little less sincere. That was when Mr Netanyahu confessed to being shocked that people thought he might have had political calculation in his mind in coming to DC. After all, it is just two weeks before Israel goes to the polls in a closely-fought election.
And this is why it was such an act of "chutzpah". The dictionary defines this Yiddish word as being an act of brazen audacity for good or bad.
Mr Netanyahu hopes it will be for good; that his appeal over the head of the American president will help sink a deal with Iran, even if it damages the president in the process - and damages relations with his administration.
But there is audacity for bad.
In Washington, where everything is partisan, the issue of Israel isn't. At times it often feels as though there is an auction going on between Republicans and Democrats over who can be more effusive in their support for the State of Israel.
But today felt partisan.
Some Democrats stayed away, while the leader of Democrats in the House, Nancy Pelosi said: "I was near tears throughout the prime minister's speech - saddened by the insult to the intelligence of the United States as part of the P5 +1 nations ... and saddened by the condescension toward our knowledge of the threat posed by Iran and our broader commitment to preventing nuclear proliferation."
The words of some administration officials are even more sulphurous. One is quoted today as saying the speech contained "literally not one new idea; not one single concrete alternative; all rhetoric, no action."
These words aren't remarkable in themselves, but are when spoken about an Israeli leader. This sort of stuff doesn't normally happen. It does now.