Giving it both barrels
This is a gift for the First Minister that he knew was coming. And he has responded by giving it both barrels.
It is clear where he is going with it. His response is not just to take a political swipe at Theresa May, although it is certainly that.
He knows the Prime Minister has no choice but to deal with a situation that she never wanted to find herself in after the election.
But he is also using the extra money included in the DUP deal to bring back to life the long-held grievance about funding for Wales, compared with Scotland and Northern Ireland.
It had gone away after the Treasury put together a new financial deal last year which prevented the money the assembly receives falling below a certain limit.
Now that grievance is back with bells and whistles. In an interview I did with the First Minister, he accused Theresa May of pitting nations against each other, and for good measure, accused the DUP of screwing the UK Government for as much money as it can in a way which is only good for the DUP. His next meeting with Arlene Foster should be an interesting one.
The pressure is now on Conservative ministers to persuade the public of the merits of UK Government investment in Wales, particularly the city deals.
Their status has now risen from being levers for economic development but also symbols of the UK Government's investment in Wales.
This may not be a bad thing for the city deals themselves which have always needed focus to become reality, particularly in Cardiff where so many different local authorities are involved.
There is a degree of predictability of this exchange. Theresa May had to strike a deal, and Carwyn Jones was always going to make as much political capital as possible.
And there is no answer. If Theresa May matches the extra £1bn for Northern Ireland for Scotland and Wales then the DUP will not have benefited above the others, and the deal is off.
But it forms the backdrop to the way that much of politics will be played out between Cardiff and Westminster for the foreseeable future.