Step-Parent's Rights During Modification of Child Support

My question involves child support in the State of: Missouri

As a step-parent, do I have the legal right to be present when my spouse and his ex discuss modification of child support before following through with the legal papers? The ex does not want me to be present. She wants it private between her and him.

And that's how it should be. It's between Dad and Mom. You have no legal rights at all in this matter.