Honestly, life isn't fair. I can understand the venting, however, you two are going to be tied at the hip for a long time because of the kids. While he has a right to 50/50, he doesn't need to come to any of your family things. That's odd. I'd also say no to the co-gift because it can send mixed signals.
There are moments in this life when you are so confident in the rightness of your actions, that not even for a second do you consider the option that you might be wrong.
