Once you get divorced, you likely have to share custody and parenting time with your ex. There are cases where sole custody is given to just one parent, but they are rare. It is usually shared.
Of course, neither you nor your ex may stay single forever. If your ex gets into a new relationship, that person may well be around your child a significant amount of the time. If you are uncomfortable with this arrangement, can you prevent your ex’s new partner from seeing your child?
You typically cannot, but there are exceptions
Generally speaking, though you may not like it, the answer tends to be no. You cannot stop that person from seeing your child at the time when your ex has custody. They (your ex) have the legal right to have the child with them, and there is nothing limiting who else they can be with.
There are some exceptions. The most obvious is if this new person puts your child in danger or if there is evidence of any type of abuse. The court does want to protect your child, and they may bar that new person from seeing them or take custody away from your ex entirely. You may also be able to ask for a court order if you worry about things like a criminal record or drug use, though the court may not grant your request.
Understanding your own rights
Sharing parental responsibility can be difficult, and it can be contentious. Make sure you know exactly what rights you have and how they are going to define this relationship moving forward.