Why in the world do you think you can not control her bringing other men around your children? Yes after divorce is final you have no say but during a separation you have power to have that written in to agreement.
Even if you are going directly to a divorce why do you think this other man will be raining your children and them calling him daddy? You are acting as if you are not going to get 50/50 custody and just disappear.
You are their father. They know it and will never be able to replace you. I was brought up in a split home from 6 on. Never once was my father replaced.
Yes there were other men around but they were not my father or daddy.
M 37 W 34
T 12 M 8 D 7 S 4
Need break 4/12/15 W no ring 7/7/15
Separate room 4/12/15 Separate living suggested 8/15 W moved out 11/1/15