Ex got with his gf when we split and I was pregnant. Although it was very hard at the beginning, I now have a better relationship with her than I do him. To the point where I very rarely see him and if I need to make arrangements I go through her instead.
AIBU to leave him out the loop? I'm essentially co-parenting with his gf! He doesn't seem remotely bothered about this and seems happy to leave us (and I suspect, the majority of the childcare) to her.