My boyfriend was ordered to pay child support for his ex girlfriends child she told him they weren't his and he asked the judge for a DNA the judge in turn asked to mother if she wanted to do a DNA and she said no so the judge is denied his request and ordered the support. Isn't there something he can do?

Did the boyfriend ever sign the birth certificate or an acknowledgment of paternity? Did he live with the girlfriend raising the child for a period?

How do you know the ex said the child wasn't his? How do you know what the judge said?

It's standard procedure for a court to order a paternity test when there is disputed paternity. So I don't find it credible that a judge would refuse one unless something else is going on here.

First you don't just "ask" a judge, I will assume you mean he made a motion and filed it in court. And in court the judge refused his motion. So this first means that there is something to the story you are not telling ? Second it would mean he most likely does not have an attorney ? And final, so after the judge ruled against him, he could appeal if the judge did not follow procedure