Sensible accord and friendly banter never last too long in the Westminster bear-pit when one can try and, occasionally succeed, in knocking seven bells out of your opponent.
And so the chief comrade thought he had caught the Tory toff red-handed when he quoted the Westminster oracle, the House of Commons Library, which had "called out" the PM over his claims on A&E waiting times; namely they were going up and not, as Blue Dave had so erroneously suggested, going down.
But the chief Conservative, nose slightly raised, was having none of it and told Red Ed that far from telling porkies, he had in fact been "absolutely right" and duly rattled off the numbers to prove it.
With Ed Balls irritating the PM with his constant hectoring, Blue Dave descended into personalising the row, accusing the Labour leader of making a massive mistake by keeping a "failing Health Secretary as the Shadow Health spokesman"; Andy Burnham, that is.
As the Tories cheered, the chief comrade rose and snapped: "I'd far rather have the Shadow Health Secretary than their Health Secretary any day of the week."
Once again, PMQs was fast rising to the heady heights of playground politics. But there was more as Blue Dave could not help mentioning the little matter of today's public sector strikes and the fact he had, by good fortune, obtained the Labour briefing on them. "It says this: do we support strikes? No. Will we condemn strikes? No. There we have it; there's his leadership summed up in one go ... Is he remotely up to the job? No!"
As the blue-rinse brigade cackled for more, the two Eds just shook their heads in unison.
Later, as the PM extolled the Coalition's growth deals for the Midlands, up popped the Port Glasgow-born Stephen McCabe, the champion for Birmingham Selly Oak, to suggest the "bribes" being offered voters just before the General Election were too little too late.
Flashman opted to use P G Wodehouse's famous quote about a Scotsman with a grievance, telling Mr McCabe: "You can probably tell the difference between a ray of sunshine and the honourable gentleman on this issue as on so many others."
The PM was talking to the Midlands MP but, in his own mind, he might well have been thinking of Alex Salmond.