Sorry, this could turn out to be quite long - want to try to give the whole picture, so as not to have AIBU by stealth 
dh won some tickets on Thursday, to a concert being held last night. 4 tickets, so whole family could go (was a family concert)
I was not thrilled at the prospect, as:
dd1 has ASD. last minute changes of plan not always ideal. concert was at the Albert Hall, so big, loud, grand, etc. tickets were in a shared box, and I didn't want dd1 disrupting it for other people who had actually paid ot see the concert.
dd1 is 6, dd2 is 3, btw. concert started at 7pm - the time they normally go to bed. neither has ever been kept up late for anythign like it before. both have been to shows, but more of the DIsney on Ice variety, or panto, where it doesn't matter so much if you wriggle/talk etc.
but I agreed to give it a go - nothing ventured nothing gained.
all went reasonably well, but both girls were a little overawed by the occasion, and were very clingy. as usual, I got to sort them out (make sure they didn't fall over the balcony/drop stuff over. keep them sitting nicely. make sure dd1 didn't get her hands on the nibbles (food intolerances)etc. dh got to chat and socialise with everyone else, again as usual.
once we were there, it was apparent that dd2 (newly toilet trained) had a bit of a runny tummy. not serious, but when she needed to go, she needed ot go, and stools were a bit loose (sorry TMI)
My job, as usual was to keep dd1 calm (happy with htis role - it works best for us as a family), so dd2 went to the toilet with dh. 3 times in the first half (80 minutes)
then came the interval.
dd1 was a bit confused,a s there were more nibbles/food she couldn't have, and she tends to think the interval is the end, so gets confused as to why we aren't going home. dd2 needs the loo again, so I tld her to ask dh.
she came back, and said "daddy says he is talking" (as he was). I check with dd1 to see whether we could all go. not viable, so send d2 back to dh to ask again. she comes back again and says "no, mummy, daddy says he is still talking". 10 seconds later she poos in her pants - which obviously means I then have to drag dd1 along ot the loos too, clean up dd2 (quite distressed - she has never had an accident since toilet training). upset dd2 means upset dd1, who is also upset because she think we are supposed to be going home, etc etc.
so, i get back, hiss a "thanks a lot" to dh, who grumpily tells me that he was talking to the CEO of the charity (concert was in aid f charity) and so he couldn't just leave in the middle because dd2 needed something.
I htink he could have easily made his excuses - surely anyone understands a small child needing the toilet (CEO is female, if this helps for information purposes, and has children herself)
mitigating circumstances on dh's side:
his company were sponsoring the concert, and we were in the company box. (although dh was NOT there in any official company-representative way, but only because he had won the tickets in a raffle). dh is reasonably senior in his firm, and I can see that it might have been mildly embarrassing as a situation, but then he was the one who insisted we tried to go as a family.
I was not shirking the taking-to-toilet duties (as he now claims - when we spoke today about it, he said "but I'd already taken her 3 times!"), but was making sure dd1 was calm and happy.
he says that there is no way I could have expected him to stop talking to the charity boss, I say he was an arse who should pull his finger out.
so, AIBU?