Non biological parent relinquish children

Our son was served papers saying girlfriend artificially insemminated gave birth to twins. She claims she was on heavy meds after birth and when our son demanded his name be put on birth certificates, she agreed to it. He didn't know the children were not his until later 4 days after birth. They are no longer together. She wants his name removed from birth certificate. Summons says: A) declaring the non-existence of a parent-child relationship between respondent (son's name) and the minor children (children's names); B) ordering that son's name immediately be removed from minor children's birth certificates; and C) For such further relief as the Court deems appropriate. I am concerned about C. Will he have to pay child support, and will he be responsible for paying court costs and her attorney fees? Note: when they split up, she told him, he would never see the children again.