Hey Tyler, I can understand your frustration and need to connect more with your son. I am divorced and can relate to the feelings involved.
I think it's important to run ideas by each other before involving the children. As hard as this is to do, I think it's important for the sake of the relationship and the trust between you and your ex.
I was recently very upset at my ex because he took my daughter to an amusement park one day with some woman he is dating WITHOUT TELLING ME FIRST. I thought it was only fair I be the first one to know that he is dating someone, not my daughter. I know your situation is different, but I came to learn that the safest course of action is talk to each other first before involving the children.
Just treat this as a learning experience and don't get too pissed off. My ex and I were able to move past our disagreement about what he did by having dinner together and honestly talking about our feelings. I hope you'll be able to do that with your ex and have you see her side as well as her understanding your needs. I was pleasantly surprised that when we aired things out and set some ground rules that we could both live with, the tension went away (or was greatly reduced).
I hope you are able to do that as well.
Take care,
Laura