The opening three months of 2013 just about sum up the flavour of this coalition: one-third desperate unity, two-thirds mutual loathing.
It was in order to address the latter that David Cameron and Nick Clegg began their year by striking a note of togetherness. Their midterm review was supposed to inject a bit of sprightliness into their ailing alliance. Instead it served to highlight their broken promises, underlining the challenges of running the country together now there is more of this government in the past than there is ahead.
The differences bubbled away throughout January. Boundary changes saw the Lib Dems stick to their guns and defeat the Conservatives, triggering "fury" among Tories desperate to get away from their despised colleagues in Whitehall. Discovering that this was the issue, of all the others, where the junior party were finally discovering their backbone was too much for some Conservative MPs, who spent at least a week quivering with anger. On gay marriage, the fundamentally liberal Liberal Democrats clashed with the forces of dark-country-lane conservatism. And on Europe, Cameron's promised referendum prompted Lib Dems to call him "stupid". Not a good period for Con-Lib Dem relations.
Then came Eastleigh, popping the swollen blister open. What emerged was not pleasant. A festival of infighting followed as the grassroots threw everything at each other. It was not a pretty sight, and one the residents of that poor, drab, otherwise anonymous southern town were forced to endure for three long weeks. Even allegations of sexual harassments levelled at the party's former chief executive Chris Rennard and the impending conviction and jailing of former minister Chris Huhne didn't dent the Lib Dems sufficiently to cause an upset. But after the shockwaves which the scandal sent rippling across the party at its spring conference, neither party emerged from February as real winners.
Another side-effect of this regrettable by-election has been its impact on Ukip, which continued its rise and rise in the opening months of 2013. What is good for Nigel Farage is bad for Cameron, who has found himself threatened by leadership manoeuvrings from figures like Theresa May, Boris Johnson and others. The PM's answer is to send forJohn Hayes, making him a 'senior parliamentary adviser'. As firewalls go, he may not quite be up to the job in the battleground of the Commons tearoom.
Still, let's not forget that one-thirds of unity. For where January and February were dominated by factions and fighting, March saw the coalition unite around what even the enemies within have taken to referring to as its core 'mission': deficit reduction. Even despite the calamitous news of Britain's triple-A downgrade, George Osborne stuck to the course in his fourth Budget on the understandable grounds that he has no other choice. This government is committed, whether you think its policies are to blame for the ailing economy or not. The chancellor may have had less wiggle room than a commuter on the Central Line, but he made the most of his options to keep the Lib Dems happy and try and win over a few working class voters, too.
So the coalition enjoys an Easter break with the memory of Osborne's Budget papering over the cracks of the coalition. The bleak unity he provides will be of little comfort to anyone in the government, or sitting on the government benches, this holiday. This was a Budget which summed up why the two parties can't afford to be without each other: for better or worse, they are tied together.
It will almost certainly be for the worse. Like all marriages, though, it takes a lot of pain and suffering before a decisive break is made. The next big stress test to come will commence immediately after the return to parliament, when campaigning begins in earnest for May 2nd's local elections. These are almost exclusively a Conservative vs Liberal Democrat affair. Magnify the trauma of Eastleigh on a national scale, and you'll get an idea of what we're in for.