This is complicated so bare with me. First, if he is not currently paying support you do not have to let him see the child. But he could go to court to seek his parental rights, he would be required to provide support, and you couldn't keep him from seeing the child. If you listed him as the father on the birth certificate there is very little you can do to prevent it. If he is not on the birth certificate, you can deny that the child is his and he would be responsible for proving that the child was in fact his, i.e. pay for DNA testing. The bottom line is you do not have to let him see the child unless and until he decides to pursue it in court.