I get a lot of what you mean and no matter how I rationalise it, its still unpleasant to see my son giving OM a hug or hear my kids talk about the stuff they do (I simply can't compete financially with all XW and OM do with the kids).
But equally I know I have to get over it because the only person suffering from my dislike of it is me and there is jack all I can do to change the reality. I can only change my reaction.
I take some comfort in the fact that my XW is being pretty reasonable about things, if somewhat inconsiderate. But I did make sure the childcare agreement assumed she wouldn't be so that if we have to default to that I'm protected for things like father's day and birthday.
It's a shame you have to tell him things repeatedly but in the end incompetence is a far better explanation than deliberately problematic.
Hope you have a good weekend
Both mid 30s, 2 young kids BD 7sep14 XW moved on long ago, now living with OM1 D paperwork in progress