Argument w/ my Father-In-Law & Step MIL

So my husband, his brothers, and sisters have never had a relationship with their biological father, EVER, but my husband keeps in touch with him only through FB. My brother-in-laws and SIL's don't care about keeping in touch with him and will get upset when anyone brings him up due to a bad history with him and their mother. They all grew up referring to their Stepdad as dad and still do. Anyways, when my husband and I first got married his family congratulated me and all wanted to be my friend on FB. (All of his family lives 30 hours away from us, so they are big on communicating through social media than by phone/text). So I reached out to my husband's biological dad to inform him of our marriage being than my husband speaks to him and he blocked me! We had never spoken before but He knew who I was b/c my husband always post pics of us together on his page and occasionally tags me in the pics. And on top of that his wife (my step MIL) sent me a request to be my friend so they all knew about me. My step MIL started commenting on a lot of my post, being friendly I guess..and then my FIL finally one day unblocked me (like 2 months after our marriage), b/c he sent me a friend request and I accepted. He never spoke or inboxed me but occasionally would like some pics of my husband and I would post and always speak to me husband but never towards me. The argument started when I found out my FIL and Step MIL were in boxing,commenting and flashing my husband's baby mama around like she was his wife and not me. They would have full blown conversations with her, tell her that they loved her, share her pics,etc. My husbands babymama has gave us nothing but hell every since the day she found out about me. She harassed us for months, threatened us, and even made it where my husband could no longer get or see his kids. So I confronted my husband and told him how I felt disrespected and he agreed that they were wrong for flunting her around but never trying to communicate with me and blocking me so I then confronted my FIL and step mother and told them how I felt about it and they apologized but a few days later were bk to doing the same thing with the baby mama. So I took it upon myself to delete and block them both from both me and my husbands page. I feel like if they can't show me any respect then they won't be able to talk to my husband and I anymore...especially when they were aware of how the baby mama was treating Us. Am I wrong for how I feel and blocking them?