My stepsons are, in theory, resident with their mother and visit their father and me every other weekend (Friday-Monday), every Tuesday night and half the holidays. My partner also sees the boys during the week (drives them to school, has lunch with them, takes them to tennis, doctor etc).
It is currently the Easter holiday and, in theory, the boys were due to spend the first two weekends and the week in between with us (we took them ski-ing) and the second week and third weekend with their mother.
Their mother has forgotten that it is her weekend this coming weekend, she has arranged to go away and can't have the boys. What's more, it's her eldest son's birthday on Saturday.
In their position I would be terribly hurt and I think that this is very damaging behaviour on her part and that my partner needs to ensure that this doesn't happen again. But I would be interested to know what you think and whether I am overreacting.