It was the last education committee before the end of term and spirits were high. A couple of the inmates got a little over-excited - who doesn't when Santa's coming? - and became engrossed in conversation. Trouble was it came in the middle of Education Secretary Fiona Hyslop's evidence on the petition for smaller class sizes from the Educational Institute of Scotland.
A steely stare, followed by a polite cough, from convener Karen Whitefield went unnoticed. She took a different tack and, adopting her best school-marm voice, gave MSPs a ticking off.
In their defence, however, Ms Hyslop had asserted on a few occasions that she didn't want to sound like a broken record - which, of course, meant she did, not least because the committee had returned to a few of its favourite themes.
Labour MSP Mary Mulligan once again asked the Education Secretary to estimate the cost to government of reducing class sizes to 18 in P1 to P3.
And once again, Ms Hyslop told her the Convention of Scottish Local Authorities had signed up to a package of measures and the costs had not been itemised.
Ms Mulligan said she found this not just "frustrating" but "unbelievable". Ms Whitefield hopped on her own hobby horse, asking what - if the Government wants "year-on-year progress" on class-size reductions - was its definition of progress? Just that: "year-on-year progress", Ms Hyslop explained gnomically.
Labour MSP Ken Macintosh allowed Ms Hyslop to change her record. He wanted to know if new schools such as Mearns Primary in East Renfrewshire, built under public-private partnership (in his constituency, of course), would be allowed two teachers in a class of 36 pupils to save inappropriate adaptations having to be made.
A bit of a skirmish about the pros and cons of PPP followed, before Ms Whitefield stepped in again to get things back on track.
Ultimately, Ms Hyslop said, she would prefer to see classes of 18 with one teacher - but "if councils want to make representations, we will listen to them".