Thanks for the chance to help. I am an attorney with over 12 years military law
Ma'am, I am sorry for this dilemma.
The truth is that nothing either of them (your spouse or the other woman) sign today would prevent either of them from contesting paternity after the birth of a child.
After the child is born, she could request a court order a paternity test on your spouse to determine if he is the child.
Your spouse could request she and the child be subject to paternity testing to determine if he is the father.
And her spouse could request paternity testing to determine if he is the father.
You are the only one here that would not have standing (the right) to demand a paternity test.
Now...such orders would need to come from a court...and it would be much easier to obtain them from a US court (there are legal hurdles in obtaining such a test in a German court). So this could be a timing problem for one or more of the parties if they have to wait for your spouse and/or the other woman to return to the states.
But this is something that the US courts can order (DNA testing)
Again, anything either your spouse or this woman sign would not preclude them from filing with the court at a later date.
The one other dynamic you do not mention is the fact that under military law that they both could be held accountable for criminal misconduct. Adultery is a crime under military law.
That is one thing you could do, if you were so inclined, as could her spouse. Either of you could report this to their respective commanding officers
and ask that they be investigated for adultery. I am not suggesting that you take this course of action, as it could lead to the end of one or both of their military careers. But it is something that could happen if the commander is made aware of this misconduct.
Please let me know if you have more questions...happy to assist if I can