Torn between picking my battles and being walked over!

[HiccupHaddockHorrendous]

Ds is nearly 14 (yr 9).
There are no lessons during the last week of school. In yr7 and 8 they went on school trips, did workshops, sports day etc.
This year, his year group don't have a brilliant timetable of activities...no school trips and he hasn't been picked to do anything for sports day (sport/games is his favourite part of school) so has been begging to be allowed to stay home.
On Friday (2nd day of no lessons), I agreed to let him stay home for two of the remaining three days after he'd come home really miserable because they'd watched a High School Musical-type film.
This morning is one of the days he picked to stay home and he's in such a grumpy mood and being generally unpleasant. I'm not at my most patient this morning and told him he'll more than likely be going to school tomorrow if this is how he's going to behave.
I'm not happy about him being at home. I feel like I've been duped into letting him stay home and he doesn't even have the good grace to be civil!!!! I don't normally let him skip school just because he doesn't fancy it and I would usually encourage him to join in with the activities but they did seem rather like school work. However, I wish I'd tried harder now to make him go and at least try them out.
And things had been ticking along nicely the last few weeks

[ChocolateJam]

It's difficult, isn't it? I'm not in the UK but have a DD the same age and went through the same thing end of last term. Our rule always used to be that if it is a school day you go to school, but when almost nobody else goes and they don't do anything constructive it feels unreasonable to force them to go. However, given that he was grumpy and unpleasant today I think you can simply tell him that staying home clearly did not make him happy and he was miserable company so he is going to school tomorrow. No negotiation.

[neolara]

I would be annoyed at the school. Given the hysteria over kids taking time off for holidays, it's pretty outrageous that the school is not offering a proper timetable of activities. I think it's fine to have no official lessons provided they are offering suitable alternatives. Watching crappy films just doesn't cut it.

[HiccupHaddockHorrendous]

Thanks, both.
I left him a list of jobs to do, ranted a little more and took myself off to the swimming pool to cool down.
He had miraculously turned back to his normal self and apologised when I got home so all calm again for now.
Roll on end of term!!!