Do not reveal how you know. Do not reveal what you know. Just reveal that you do know:
These words may become useful in your future (if you find out about A or OM): "We both know you are lying. When you are ready to tell me the truth, I will listen."
As far as kid discussions, keep them business like. Treat her like you would a hostess at a restaurant. Friendly, no personal details, just parenting talk. Listen and validate. Set boundaries on how you want to be treated.
"What is best for my kids is best for me" Amor Fati Link to quotes: https://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=2879712
