My sons biological father has barely been in my sons life. I asked him to give up all his rights so my finance would be able to adopt him when we get married. He told me there was no way he would do this. So, I told him he couldn't see him anymore. Why all of a sudden when I tell him my finance wants to adopt him does he want to step up and be a father. He told me he would take me to court and file for at least partial custody. My finance and I are wanting to move out of state and if he takes me to court we won't be able to move. I don't want his biological father to ever see him. What can I do?

You need to remember that it's not all about you and your future husband. It's about your child, who has the right to have a relationship with his father, whether YOU want him to or not. Unless you can prove that Dad is a danger to his son, he has the right to spend time with his son, and the court WILL give him partial custody. If it comes out that you've been keeping them apart, and that you don't want Dad to EVER see him, he could get even more than just partial custody. You need to start playing nice... you created a child with this man, and now you're going to have to accept that he's going to be around for the rest of the child's life.

Had to spread it but I just wanted to say Brilliant answer!
Exactly right. Play nice or lose more than you would like to.