How Can I Limit My Ex From Seeing Our Son or Get Supervised Visits

[myl1lman]

My question involves a child custody case from the State of: New Hampshire

I wasn't 100% sure of what to put this under. My ex keeps coming and going wanting to see my son, paternity hasn't been established he isn't on the birth certificate my fiance is which my ex does know of but we don't have it on paper that he knows and agreed to it. He wants to see him unsupervised but has no idea how to take care of him, change diapers, feed him, etc. But when i tell him know he threatens me with a laywer. I've offered for him to come to my house and even for me to go to his parents house where he lives. he is 18 and doesn't pay or support in anyway. What are his rights and mine? What can I do?

[Dogmatique]

Please clarify - who is on the birth certificate? Who signed the paternity papers?