Fiance Adopting New Baby

Here is the deal. I met my now fiance about two months after I got pregnant (I am due in 6 wks). He wants to take full responsibility for the baby and start our family. My problem is this. The biological father has gone back and forth on being involved, but recently, because I have to fill out all the legal forms now, will not respond to me. I wanted to know the legal repercussions of just putting my fiance on the birth certificate. And if this is not a smart thing to do, the easiest way for him to adopt the baby. Any ideas? I live in FL and the biological father lives in TN. Any help anyone can provide would be appreciated.

Putting your fiance's name on the birth certificate is fraud. Don't do it. Your fiance could not legally adopt your child unless: 1.the bio dad agrees to TPR and 2.you and your fiance are actually married (I am pretty sure this is a requirement but not 100% positive-someone else in this forum may know for sure).
The bio dad has the right to be involved in his child's life. Your child has the right to receive financial support from daddy. Knowing he may have to pay child support might make him swing one way or another on his involvement in the child's life. He may be willing to sign away his rights in an effort to avoid child support. No matter what, get a child support order ASAP. You never know what can happen