From my experience(same deal as you) it will hellp you when it comes to alimony. If you can provide info about the cheating(i.e pictures, emails...)then you should now be paying her APL not alimony. Reason being,after divorce is final she is no longer able to get APL-because of the adultry. Alimony she can get, but APL she cannot. As for custody-each case is different, I doubt the adultry will help but it sure wont hurt. Hope i helped out.