I need some advice

Never have I been with a man who has a child with and have to deal with his ex as well. His daughter is 4 years old and I am now currently 7 1/2 months pregnant. His daughter lives with mother in Ft. Worth and we live 4 hours away. Weve been living together for almost 3 years now and he still till this day keeps me distant from his ex. He says he doesnt want to hurt her feelings and she does not like me. He says I should respect when they talk due to the fact he is living with me and she is alone. Yesterday he was face timing daughter and her mother which always almost 100% of time is on phone as well and shows her face or wears skimpy clothes while he talks to his daughter. So I in background said Hi we miss you and he got mad at me. He said why did I do that. Also note his daughter stays with us all holidays and if not we visit weekends so she is very used to me. He then goes off on me and tells me I'm disrespectful and do not care and all he cares about his daughter. How I need to respect his wish and hers to not be around. He yelled at me and told me to shut up and left house since I let him know she should know I'm here and you need to treat myself and our baby as important as they are. Am I being overly dramatic? Is this something I might have to deal with the rest of our lives together? Should he show her how important we are and not keep us separated. I feel he needs to not treat me as a friend or still try to hide me. Like why does he care so much of what she thinks. We are the ones in the relationship they are not no more.