Crikey OP, if they’d never had a year on / year off system for Christmas, you’ve approached this to almost set yourself up for failure. This is something that should have been raised months ago, not 3 months away.
from mums perspective it’s very convenient that he never asked for Christmas until he became a big happy family with someone else. I’m not saying that’s how it is, I’m saying that’s how it feels for her.
Even the lowest conflict mother would be upset to hear that someone has unilaterally decided that the standing arrangement of her having her children with her for Christmas is being challenged.
she hasn’t thrown a spanner in the works, that’s your household throwing the spanners.
this needs to be a discussion and really should be approached sensitively & from a place of what’s fair & best for the children.
what do the children want?
I’m a step-parent, not a mother. I put up with some absolutely mad shit from DHs ex girlfriend. I don’t love the woman for many reasons. But I do have empathy & I know it hurts her when her kids aren’t with her Christmas Day, it’s been an arrangement to rotate ever since they broke up long before I or her husband came on the scene & almost a decade later it still upsets her to not have them there (not that she’d have the same empathy for DH mind, he generally gets a barrage of abuse by text throughout the day for daring to want to speak with the kids Xmas morning when it’s ‘her’ turn). But whatever feelings I may have for the woman she’s the kids mum & if she’s struggling it affects the kids. Please try & put yourself in her shoes. It sounds like you & your ex have been really sensible but it hasn’t happened that way for her & your DP. She’s probably very surprised by all this.
initiate a proper conversation for future Christmas plans.
he was a bit silly too booking a holiday for a week he’d previously been expected to have them (sorry if I read that wrong).