MPs find themselves in government - and in opposition
For politicians, one of the benefits of devolution is that it allows them to be in both government and opposition at the same time, cheerleading for one administration while lambasting another.
Prime ministers's questions, or PMQs, is the half hour in the parliamentary week when the prime minister is directly accountable to MPs, answering questions about his government's responsibilities.
But this is politics, so he is often asked about the responsibilities of governments and politicians elsewhere.
Today, he was asked about the Welsh government's decision not to follow the decision by ministers in England to enable local authorities to freeze council tax bills.
Here's the question from Tory MP Guto Bebb: "A typical council tax payer in my Aberconwy constituency will now pay £124 more than they did in 2010 because the money made available to the Labour Welsh government has been used to fund their pet project to secure their majority in the assembly. Does the prime minister share my concern that hard-working families in Wales are being used in order to fund the Labour party's pork-barrel policy in Cardiff Bay?"
Not surprisingly, given their shared party affiliation, David Cameron thought Mr Bebb had a point: "This government have made available money for a council tax freeze. That has the consequence that money for that freeze is available in Wales, so people in Wales will know who to blame if their council tax is not frozen. It is the Labour assembly government in Wales: they are to blame; they are the ones who are charging hard-working people more for their council tax."
Mr Bebb's colleague, Alun Cairns, focused on a government further from Westminster at Scotland Office questions before PMQs. Mr Cairns wanted to know if the (Liberal Democrat) Scottish Secretary, Michael Moore shared his "disappointment" that the Scottish government had rejected the idea of new nuclear power stations there.
Mr Moore resisted the bait: "Clearly, there is a significant contribution to our current energy mix from nuclear. You will be aware that planning on these matters is devolved to Scotland. It is a matter, rightly, for the Scottish parliament to determine. For my part, I am delighted that we are seeing an increase in the proportion of renewables in our energy mix as part of a sustainable, affordable energy supply in the UK."
Of course, the government/opposition mix isn't confined to the Westminster coalition partners. Labour Welsh First Minister Carwyn Jones was swift to criticise last week's deal to cut the EU budget. "The prime minister says this is a 'good deal for Britain'," he said. "He will need to explain how it's a good deal for Wales. The Welsh government has always recognised the need for discipline in the overall EU budget but it cannot be right for EU money allocated to the UK to be siphoned away from poorer regions, like west Wales and the Valleys - to richer regions elsewhere."
Mr Jones also criticised cuts in the common agricultural policy budget - although at Westminster, Labour leader Ed Miliband said the cuts in spending on farming didn't go far enough. Overall, Mr Miliband welcomed a cut in the EU budget that Labour MPs had voted for (against the wishes of the prime minister).
Today, five days after the summit ended, Mr Jones has issued another statement. "Overall," he said, "where the agreement failed to provide adequate support at the EU level for our vulnerable communities, we will be looking to the UK Government to cover the shortfall."
Mr Miliband may be genuniely relaxed about post-devolution policy differences between Westminster and Wales but as Labour MPs voted to cut the EU budget, it's difficult to see the Westminster coalition writing a cheque for the Welsh government.