Often my ex husband was away from home with work and no one came to help me with my children. I did once leave to go to a B&B, after a row, but returned after a couple of hours as I couldn't leave them overnight without me.
I got my first break away on my own when mine were 26 and 16 years old! I have just booked my first spa break weekend away in a few weeks while my DS has a final get together with his college mates before they all go their separate ways.
In saying that, my ED, up to the time that I last saw her, had never left her children for any pleasure activity, work yes, but not holidays etc, not even a night out together with her partner. I think that this is wrong. I do think that you should put your relationship first at times and make time for each other or even yourself. I know I would have loved it if I'd have been assured that the children were properly looked after at home. As it were, if I just went out for a while, I came back and my ex hadn't even given my daughter a drink most times. So I never felt able to leave them with him for long at all.