The Labour lads and lassies were a little cranky. They were feeling a tad green and hairy. A bit gooseberryish.
It was bad enough that the junior coalition partners had to watch Gerry Adams and Micheál Martin stride across the plinth side-by-side in a 'Reservoir Dáil' scenario.
Now they had to sit in the chamber and take in the sight of a demure Mary Lou McDonald playing nice with Fianna Fáil deputies.
The Sinn Fein deputy leader is rarely of a mind to play nice with other parties, tossing spears of sarkiness at all and sundry.
But yesterday she was a Shameless Shinner, professing perfect accord with both Micheál Martin and Barry Cowen, raising the grumpy levels across the floor. Joan Burton was taking Leaders' Questions as usual, and Barry was grilling her on water charges-related issues, and the Tánaiste was striving mightily to provide him with the lengthiest possible replies.
There was more than the usual heckling from the government, with Paul Kehoe suggesting that Barry "should walk out with Mary Lou".
Then it was Mary Lou's turn, and she resumed the line of questioning which the Offaly deputy had quit in despair of getting a straightforward reply from Joan. "Perhaps you might make an attempt at answering this time?" suggested Mary Lou tartly.
Joan set off on an attack on Gerry Adams. "The most erroneous figure I heard this week was the Deputy's leader suggesting that water charges were €3m and the property tax was €5m in a debate with me on RTE," she sniffed.
Fianna Fáil's Timmy Dooley gave Mary Lou a dig-out. "That was the only time you beat him in that debate," he ungallantly told Joan.
But the Tánaiste swiftly rallied. "I know at the moment Fianna Fáil and Sinn Féin are looking pretty on the plinth but in all honesty, could I answer your questions?" she sniped back to the Sinn Fein deputy.
But Mary Lou was saving all her sark for Joan, and taunted her time and again about what she saw as the Tánaiste's predilection for taking the scenic route to an answer, akin to a dodgy cabbie with a foreign fare from Dublin airport.
She repeated her question to Joan, adding: "Although I have lost any real expectation that the Tánaiste will hear what I am about to say to her again".
But when the Order of Business began, Mary Lou was all charm again to her Fianna Fáil friends.
Micheál Martin was on the warpath once more over the Ceann Comhairle ruling out a Dáil debate this week on the establishment of a commission of Investigation into claims of garda malpractice.
The Fianna Fáil leader was up on his soapbox defending democracy, and giving it welly. "The idea that a parliamentary assembly could be silenced by a judicial review or a writ taken by a Member of the House is the very antithesis of parliamentary democracy as we know it," he declared.
The Labour troops weren't impressed, and deputy government whip Emmet Stagg loudly insisted that Fianna Fail's own whip had agreed in advance on the proceedings of the business.
Micheál suddenly rounded on Emmet. "How dare you!" he bellowed.
But he found support in another quarter. Once again Mary Lou rose to speak. "I concur entirely with all of the sentiments expressed by Micheál Martin," she announced unabashed.
"We cannot have a situation in which the work of the Oireachtas , be it on the floor of the Dail or in the committees, can be brought to a halt because someone runs to the courts pre-emptively or otherwise, lawyers up and sends legal letters".
Yep. There was indubitably a striking similarity to the respective hymn-sheets of both Mary Lou and Micheál, united (even if just temporarily) in song like politics' own Sonny and Cher.
But of course not even their combined indignation could sway the Tánaiste, who contented herself at hurling the occasional dig about the new pals.
Oh that Mary Lou wan is shameless altogether. It'll all end in tears, mark my words