If I want to go on holiday, I have to ask someone to have my ds. I have to ask my boss for time off. I make all those arrangements before I just "decide" to do something for myself without ds. If I can't arrange things, I don't go. I don't just decide I have a "right" and go.
In my case I have long given up asking my ex to have ds, I just ask and pay other people.
However my dp ex just books a holiday for herself and her boyfriend without consulting anyone at all. Both dp and I work and have to juggle work to look after 4/5 kids but apparently we don't have any "right" to be consulted, we are "told". We, our bosses, our clients, our families, our resident children all have to fit round the whims of the ex wife because we would be out of order to expect to be consulted!
Had we actually had any say in things and been able to negotiate dates or given more than a few weeks notice we might have been able to ensure the kids had a nice time with us instead of being passed from pillar to post or left home alone.
Ex's who continually state that they have the best interests of the kids at heart, sometimes need to take a step back and look at their own behaviour. 