We are signed up with sitters! The last two times I've tried, they've said they can't fill the booking, but they only tell you 24 hours beforehand which is nowhere near useful as if you're relying on them, it means having to cancel your engagement at the last minute. They've admitted that they're short of sitters in our part of the country so am thinking of quitting, it's just a subscription for no real benefit most of the time.
The concert admittedly it was 2 hours of concert but 1.5 hours each way on the train plus faffing time, so not fair to say it was just 2 hours for £50 
but it does add up for one night out in a blue moon. Plus, since we're in minor league moaning about dh's mode, it really pissed me off when he said "do we have a babysitter sorted?" as in I haven't done anything, I assume you have... Not even "have you sorted the babysitter" which would imply that he appreciated that I'd done it, more than somehow this magical Mary Poppins would come out of nowhere!
Beans, your sentence that it's your job to facilitate his life, not sure about that - he supports you financially, but that doesn't mean that it's his right to do whatever he likes! You stay at home to facilitate his going out to work, so that he doesn't have to stay home and look after the girls, but once it's outside the "working day" everything should be equal.
Indith, you are so wise!
McKayz, the self settling thing is such an epic... I fed to sleep for both of them until over 1, then we tried the no cry sleep solution, fortunately I think E did better as she had S there in the room with her.