Ex-Husband and Married Girlfriend

My ex-husband and I have joint custody of our 14 year old son. Our son resides primarily with his father in Greenville, NC because of travel involved with my work. My ex-husband recently moved his girlfriend permanently into the home with my son. My ex-husband’s girlfriend is still married to her current husband and to my knowledge has not even filed for legal separation even though she moved everything out of the home with her current husband and immediately into the home of my ex-husband and son…literally. My son is extremely upset and uncomfortable with the situation. He has shared with me that he is being teased at school because the fact that she is still married is common knowledge. When I tried to address my concerns and my son’s concerns regarding this issue with my ex-husband he stated that I was jealous and that it was none of my business because we were divorced. I am strongly considering having my son come live me with me and arranging for a nanny or relative to stay in my home when I travel which is only 1-2 overnights per week. Would this be a possibility and if so what steps do I need to take in order to become the primary custodian?

If you have a court order in place you must file for a modification of custody. The court can modify custody when an action for the same is based on a substantial change in circumstances affecting the child.