Have the case dismissed as the former boyfriend has no standing in the matter. The only ones that can contest it are the Father (husband), Mother or child.
Quote:
Subd. 4.Action to vacate recognition.
(a) An action to vacate a recognition of paternity may be brought by the mother, father, husband or former husband who executed a joinder, or the child. An action to vacate a recognition of parentage may be brought by the public authority. A mother, father, or husband or former husband who executed a joinder must bring the action within one year of the execution of the recognition or within six months after the person bringing the action obtains the results of blood or genetic tests that indicate that the man who executed the recognition is not the father of the child.
Ref:
https://www.revisor.leg.state.mn.us/statutes/?id=257.75