Man raised as son for 50 years faces paternity lawsuit from stepmother after father's death

A man who spent more than 50 years living as his mother's son has sought legal advice after she sued him to deny their parent-child relationship — a move he believes was triggered by a dispute over his late father's Seoul apartment.

The case was featured Thursday on YTN Radio's "Jo In-seop's Legal Clinic," involving a man identified as A, who is approaching his 60s.

A's father remarried when A was 4 years old. A was registered as a biological child born to the couple, and the family of four lived together after a younger sibling was born shortly afterward.

But A said he grew up feeling discriminated against by his mother.

She would secretly give his younger sibling better food, always took the sibling's side during arguments, and began keeping her distance after A completed his military service and moved out on his own.

Then his father died. The father had owned an apartment in Seoul, but because his mother continued living there, A said he never raised the subject of inheritance.

After that, his mother and sibling began avoiding his calls, and A was left to hold his father's memorial rites alone.

Three years later, his mother filed a lawsuit seeking confirmation that she and A had no biological parent-child relationship, and also requested a DNA test.

"Given that the inheritance issue had been left unresolved, receiving this complaint makes me think it's about the apartment my father left behind," A said, seeking advice. "Even if we've lived as mother and son for more than 50 years, if a DNA test shows there's no blood relation, does that mean I'm legally no longer her son?"

Attorney Kim Su-jin said that if a person has been registered as a biological child despite having no blood relation, an interested party can file a lawsuit to confirm the absence of a biological parent-child relationship — but added that this does not automatically negate the legal parent-child relationship.

Kim said the Supreme Court has held that even if a birth registration was made falsely as a biological child, if it functionally served as an adoption, the legal parent-child relationship cannot be denied unless there are special circumstances warranting dissolution of the adoption.

Kim went on to say that for an adoption to be recognized, there must be a clear intent between the parties to form a parent-child relationship, along with the actual fact of having lived as parent and child — including raising and caring for the child. The mother had accepted A's existence and registration while aware of both, the two had lived together as parent and child for many years, and there were indications A had fulfilled his duty to support her as an adult, Kim said.

Kim said that if such circumstances accumulate, the substantive requirements for adoption could be fully recognized even without formal adoption paperwork. "If it is recognized as an adoption, this lawsuit would be dismissed and the legal parent-child relationship could be maintained," Kim said.

Kim advised A to prepare a copy of his resident registration record showing that he and his mother shared the same address for an extended period, and to gather bank records or receipts showing exchanges of tuition, medical expenses or living costs.

Kim added that official documents listing the two as mother and son would also serve as strong circumstantial evidence, and that written statements from relatives or acquaintances confirming they had known the two as a genuine mother-son pair would also be helpful.