Venting 😢

My sons sperm donor & I broke up before I found out I was pregnant. My son is now 2 mos old & his dad doesn't call to check on him, hasn't even met him. He has known this whole time that he has a baby, and that I am all for him stepping up, no courts involved, no drama. Just solely what's best for my son. Well I never hear anything from him, then earlier he likes a picture of my baby on Instagram and it pissed me all the way off because he doesn't care for my son, but you have the nerve to stalk my page and like his pics? So I texted him and asked him how it felt to have a beautiful baby boy that he has never even met... He calls me and acts like "what kid" "what are you talking about" "why are you starting shit" blah blah. I said why are you acting like this, you KNOW you have a son, you have since day one, Kieran looks just like you.. He says "who's Kieran" and my mind went red, I just hung up and cried to my mom because "who's kieran?" Kieran is my beautiful baby boy, he is my everything.. And he knows who Kieran is too. He knows damn well who Kieran is. He said that to be a jerk. It just really hurt me that he is acting like that about my baby. The protective mama bear in me I guess. But I blocked him, on my phone & social media. I left doors open and made it easy for him to come into my sons life, but that is how he feels so why should I keep this offer on the table? I feel like if he cares he can take me to court, we can do it legally, confirm paternity, child support all that. I feel like I'm protecting my son from a man who wouldn't be any good anyways. Am I wrong?