It's not something i've really questioned before but as I am hopefully starting divorce proceedings soon, I wonder what everyone else does.
STBXH, married 17 years, together 20 years. He was abusive and controlling the whole relationship. he decided to leave last year.
it was always left to me during the marriage to arrange everything for DCs, mainly because he was working away for weeks on end and then home for (usually) the same amount of time. When he was back he would occasionally take them to activities or do school pick up etc but nothing regular, just when it took his fancy. did not help round house (except cooking because I was shit at it and practically every meal drew a criticism). i dealt with all the paperwork etc, especially when we moved to another country to where he didn't speak the lingo. he is a high earner. He didn't attend school meetings, make doctors appointments etc. Think you get the gist I.e i was secretary.
we will be arranging the divorce soon and i am loathed to give him any help. A mid 40 year old should know how to do things or problem solve things themselves right? I am loathed to give him information (not in relation to kids I add) as i feel he could find things he needs to know out for himself if he got off of his lazy arse and bothered to try. We have not been living together for over a year.....he asks me for bank details for a joint account to access it online....errr you could get that info yourself you lazy arse, it's no longer my responsibility to wipe your arse! Anyway i digress....
In my eye he is very much a Disney dad. For example, from the start of this year he has had the kids a total of 36 days at his.....plus one meal and one cinema date. The most he has had them with him is 14 days on the trot......then he needs the other 3-4 weeks obviously for himself to recover 
. he has taken them today after not having seen them for 3 months. he has them for around 2 weeks, during which time they will both start a new school ( me and Ds's relocated from other country, he followed). he asked if I wanted to arrange for both of us to be there, i wanted to take them or some other arrangement? 
. My answer was, no it's fine you can take them )I've had many years of first days of school etc).
My question is, how do people treat it when the ex takes the kids for a set amount of time? What i mean is, if he was not here (or even if he was) and I needed to go somewhere and needed someone to watch the kids, i would have to find a babysitter/family member etc during "my parenting time" with them, right? So is it the same for STBX partners? As in, even though they are my kids and I love them, should I be at beck and call if there is a reason he needs to find someone to look after them? or am I allowed to treat it as, they are with you as their equal parent, therefore it's his problem to find someone to look after them during the time he has them with him?
it's more a case of wondering how the kids feel, whether knowing mum is there but is saying "no, your problem" is detrimental to them? they are of secondary school age if it makes a difference.
Hope this post makes sense and would be interested to know how others work it. x