I'm sorry for writing so much I would just like explain the entire situation so that I can get some help or advice. :3

Okay so yesterday my boyfriend was served with "Notice and finding of financial responsibility" papers and we honestly don't know what to do, 6 years ago he was dating a woman that lied to him about taking her birth control (she had it and stopped taking it in order to get pregnant) and she ended up pregnant with twins, he refused to marry her and didn't want to stay in a relationship with her because she tricked him and tried to trap him he did want his children he wanted to be a part of their lives he just didnt want to be with her, so she picked up and moved to Mississippi with her parents (he was living in Germany at the time) she cut off all communication blocked him from social media all that jazz and he couldn't contact or locate her to see his children, years go by and he gets a call from her a few months ago and she tells him that she wants him to pay child support because her marriage has failed and the man that she told the kids was their father left and now she can't afford to raise them (she has had more children now and refuses to work) he asked if he could see his children and she agreed so we drove from Oregon to Mississippi and when we got there she wouldn't give us her home address so we pretty much took a trip for nothing she said she changed her mind and said she will never let him have any contact with the kids. We both make about 1500 a month and I just recently had a child so we need every dollar we make to take care of our family - if he has to pay the requested 600$ a month we won't be able to pay our bills. so my question is :is there any way he can refuse to pay this? or can he sign away his rights to the children I don't see where it is fair at all for him to pay for children he has never and will never have contact with.

Edit: I forgot to mention that she claims the reason he can't see his children is because of me, she doesn't want me around her kids (I went on the trip with him, yes but I had no intention of going into her home or near her children I was with him as moral support) I believe honestly that she just wants to live on child support and welfare she keeps trapping / trying to trap men and then does this to them she has done this to two other men only one married her and now that he left she is also trying to get child support from him. this isn't okay =(