Difficult separations are bad enough to deal with and they’re often made worse when children are thrown in the mix.
Prioritising what’s best for you emotionally, whilst respecting what’s best for the children, is an exceptionally tough call; so, who should win and why?
On a personal note, I struggled enormously with this one and there is no straight line solution, because it is extremely difficult to get through the day when you have a flailing ex to deal with and you know it’s not good for the children to hear you venting about how awful their other parent is behaving, either now or historically.
Children process things very differently to grown-ups and sometimes they struggle to cope with an unsolicited influx of unpleasant information. It’s next to impossible to try to make them grasp an adult relationship gone wrong, so try not to expose them in the first instance.