Steve85 - State laws. This state won't grant a divorce while a parent is pregnant here because they have a presumption of paternity, even though I can give them the date of the last time we did stuff and prove that if she is, it's not my child.
I'd look into this. I am not sure that law applies to spouses that are separated, especially when the one pregnant has another person. So don't assume. Talk to your lawyer.
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018