Once you’ve fallen in the eyes of the judge, it will be very difficult to get back up.
The judge will pay attention to your ability to keep your promises, be honest with your spouse, follow agreements you’ve made with your spouse, and follow orders of the court.
And, a real, live human is making the decision, and this human – the judge – has fairly wide discretion (ie: they are THE boss).
While what you do post-divorce is really none of the other party's business, the fact is that what we do has an effect on how other people relate and deal with one another.
Rubbing the other parent the wrong way probably won't help with post-divorce cooperation.
Now, while you may want to move on and put the former relationship behind you, if children are involved, you will be tied to that person for some length of time.
That means that although you get divorced, you are still going to have to carry on a parenting relationship with the other parent.
There are many factors a judge will look at when deciding which parent should have most of the parenting time, and one of them is the outside influences each parent will bring to the children.