A story: A family live on a farm. This family consists of a man, his wife, their child and the man's brother. The older, married brother, owns the farm, and the younger, unattached brother works with him. They all live together in a farmhouse on the land; sharing meals, household duties, and each other's space. They are happy.
One day, the wife gets sick. Despite all the care they two men give, despite the love in house, and the attention of neighbours, friends, doctors and well wishers, the wife dies. The men console each other, and the motherless infant they now care for between them. And life goes on.
They are still a family. The two brothers raise the child. They both care for the growing person, feeding, teaching, comforting, loving, growing with the child. Their three lives become entwined, and two men become parents, developing a bond more powerful than either biological connection.
And so the child grows. And lives a life. Becomes an adult with their own story. And is no different from any other child/teenager/adult along the way; with problems just like everyone else. And all three, the man, the brother and their child are happy.
And no one ever said anything about this person having two dads.