A woman called me and asked over the phone if her infidelity will affect her rights when she files for divorce. The simple answer is probably not unless it is affecting her children or she is wasting marital assets. Most judges prefer not to hear all of the details of who did what to whom, unless the facts are shocking to the court which means not the things they hear on a daily basis.
New York is a no-fault divorce state and since it has become one I can't remember the last time I saw a divorce complaint alleging cruel and inhuman treatment or adultery. While these claims still exist and certainly can be brought up during a trial, the reality is that most divorces in NY are now granted without opposition to the allegation that the marriage has broken down for six months or longer. Most lawyers will explain to their clients that it is just easier that way and less expensive than to potentially litigate these other grounds for divorce. Almost all clients will agree.
I told the caller that if she involves her children inappropriately and prematurely with her boyfriend there could be a very real impact as to whether she has residential custody of her children. If the children are older and resent the boyfriend or become angry with their mother, they may want to live with their father. If she sleeps over with her boyfriend and the children are there it will be viewed as poor parenting judgment.
If it is proven that she (usually it is the husband) that has been spending large sums of money on the other person, there could be an accounting to recover half of what was spent. Large spending on trips, jewelry, dinners out and gifts, if substantial, could lead to more controversy.
If she decides to move out and live with her boyfriend it will certainly reduce or more likely terminate any spousal support. Why should her husband support her if she is living with someone else who is or should be capable of contributing to her support.
The best advice is to keep boyfriends or girlfriends out of the picture while you are going through a divorce. The problems are complicated enough without adding another emotional layer to the situation.