So now we know: David Cameron and Nick Clegg are married, happily so. But not to each other. That was the line the Prime Minister used to deflect the inevitable marriage analogies that have followed this couple ever since their famous first date in the Downing Street rose garden in May 2010.
This time around, we're invited to draw comparisons with a car, a steam engine ... and a tin of varnish.
Half-way through their term, Mr Cameron says the Tories and Lib Dems are pressing on "with a full tank" and "full steam ahead".
Yesterday, after we were invited into Downing Street for their half-term report, he announced: "It is a Ronseal deal. It does what it says on the tin."
Yesterday's exercise was to present a united front, point out the coalition's successes and restore a sense of purpose to the Government for its final two years.
Many Tory backbenchers complain openly about having to share power with the Lib Dems, but yesterday they were firmly told that this was the right thing to do.
Any talk of an early separation was scotched, with both men insisting the deal would run to 2015.
The review document itself is notable for what isn't in it - a free vote on hunting has been dropped since the first coalition agreement - as much as its list of vague pledges for the future.
There's not much encouragement for those desperate to see corporation tax devolved to Stormont: the Government merely promises to "consider the case for devolving corporation tax to Northern Ireland".
As ever, the Prime Minister and his deputy looked at ease in each other's company.
There were countless references to taking the tough decisions together and their enthusiasm for the deal - not shared by many of their MPs - shone through.
Even on Europe, the issue where the parties are poles apart, they managed to find a scrap of common ground to settle on.
And as for Mr Cameron's recent comments that he would like to serve as prime minister until 2020, Mr Clegg said: "You shouldn't criticise a politician for being ambitious."
The challenge for both men will come in two stages: firstly, to hold the coalition together as restless backbenchers press for an early divorce; then, as the next general election looms, they will have to suddenly reinvent themselves.
The chummy consensus we saw yesterday will be thrown out of the window as they scrap for votes.
It is an intriguing prospect.