Hello and welcome to News Out from the BBC World Service.
We're coming to you live from London.
I'm James Menendez.
We journalists often like to use words like bust up or row to describe what are sometimes just disagreements.
In the case of what's just happened between President Trump and his self-appointed first buddy Elon Musk,
those descriptions feel somehow inadequate.
It was a gasp-inducing eruption of anger from both parties as their previously close relationship crumbled before the eyes of,
well, the whole world.
amplified, of course, by the fact that both men have their own social networks.
At the centre of this war of words is what Mr Trump calls his big,
beautiful bill of tax cuts and spending increases that impartial analysts say will add hugely to America's already huge pile of debt.
While it was Mr Musk who fired the first salvo on Fox News.
We've got this enormous federal budget deficit and it's a two trillion dollar deficit.
It keeps growing.
Our interest payments are higher than our defense department budget.
That's I think was the real wake-up call for me.
Until yesterday, the world's richest man had gone after the bill, not the man behind it.
He was, after all, brought in to take a scythe to federal spending.
But yesterday, from around lunchtime in Washington,
Mr. Musk wrote a series of posts on his ex-account,