He has a right to his day in court. I could be wrong but it doesn’t sound like he’s fighting for custody.
Far be it from me, a mere mortal man, to bust into a disagreement between two wimmin. Throwing caution to the wind, I believe Diana has the best idea. If he wants to be a real man, he should just quietly go away and leave the kid to have a chance to be normal. He shouldn’t have any rights at all at this point.