Muslim husband seeing his child with her mother alone in their home

My husband just found out he had a 1 year old child. The mother is non Muslim. He goes over there to see baby alone. I do not like mother’s dialogue with my husband. She is personal with him and way to intimate. She says ThIngs like it’s amazing how much she looks like us and our sleeping beauty. Yes it’s their child but there is no us or our to me in a co parenting plan. She let this child be fatherless for a year and now feels like she has some right to my husband. I haven’t met child yet and that hurts also. Please tell me if it’s haram that he is there alone? I am so lost and don’t know what rights I have. This all seems so wrong to me.