I was with my son's father for 3 years. Our son is 1 year and 10 months. I broke up with him because he did not pay any attention to my son and will ignore him most of the time. We lived with his family in a house that has 3 cats and 1 dog. On February 28, the doctor told us our son was allergic to cats and cat dander. Our son's doctor told us to get rid of the cats or our son's allergies were going to get worse. Ever since we found out our son was allergic to cats I will tell him to move out because it not safe for our son to live with 3 cats. He will always tell me no because we will save a lot of money and school was close to us. When my son started to get more rashes on his skin. I had enough and decided to move out with my son. His father wasn't really concerned about him having allergies a longest we saved money. He will always tell me to get back together but once I told him that was not going to happen he threatened to take my son away from me. Sometimes I think he is only doing that of vengeance because I don't want him back. Can I prevent my son from spending the night over his dad's house because he is allergic go cats? And will that help me get full primary and sole custody of my son?