Mahhhty,
I have no experience with navigating children's birthday parties but I am quickly approaching two in my own sitch.

I can't imagine how tough it is to organize the simplest of tasks when one parent refuses to cooperate.

Often times I've told myself that my STBX deserves to make her own choices and be happy. For a second or two, I wonder if she is happy. Then, I realize I don't even know her anymore.

Me:35 W:30
D:4 S:1
Bomb: 01/08/15, discovered EA & PA
In House Separation: 01/14/15
W moves out: 04/05/15
I tell OM's W about A: 04/15/15
W serves D papers: 06/19/15
Mediation: 09/16/15
D final: 12/01/15